Ray's 1987 944 LS1 Build & Swap

Hi Folks, I'm finally recovered from a 2-week case of the flu... and I'm trying to get back on track.

As mentioned in my last post, the TPC replacement UAC Condenser is plumbed with a #8 inlet and a #6 outlet on the passenger side which facilitates relocating the new UAC Drier and High-Low switch to the passenger side also.  With this change, all AC component connections are in-line on the passenger side and simplifies AC plumbing dramatically.

Below is a working diagram for my proposed AC system.  System lines and factory components shown with dashed lines have been removed.  New lines are numbered 1-4 and fully described later in this post.

[You must be registered and logged in to see this image.]

Before I removed the factory drier and high-low switch, I carefully documented the high-low switch wiring because I plan to reuse these and maintain my factory Porsche AC controls.  

[You must be registered and logged in to see this image.]
<Wire Connections at Harness>                                     <Wire Connections at Switch>

Next, I pulled the drier, high-low switches and factory #6 Condenser line all in one piece by simply loosening the 8mm mounting bracket clamping bolt.  The drier mounting bracket is held to the frame with two more 8mm self-tapping bolts and is easily removed.

[You must be registered and logged in to see this image.]
<Removing the Drier Holding Bolt>                                    <Factory Drier Mounting Bracket>

With the drier assembly out of the car, it was clear that the replacement #6 line from the Condenser would need to include hardware that would accommodate the Porsche high-low switches.  This is something I know next to nothing about and will likely leave to the AC shop folks to address.  I’ll focus on extending the wiring to the passenger side.

My first concern was where exactly to mount the new UAC drier.  There is ample space in front of the wheel well on the passenger side, especially if the windshield washer reservoir is replaced with a smaller unit.  Leaving that option open, the logical place seems to be the old ignition coil mount.

[You must be registered and logged in to see this image.]
<Extracted Factory Drier, High-Low Switch and Condenser Line>

[You must be registered and logged in to see this image.]
<Proposed UAW Drier Location>

Working from the front of the car back, below is a list of new custom lines that need made:

1: UAW Condenser out (HP) to UAW Drier - #6 hose with male O-Ring ends.  Includes drier end hardware to accept factory Porsche high-low switches.

2: UAW Condenser in (HP) from Sanden GM Compressor - #8 hose with male O-Ring ends.

3: UAW Drier out to factory Evaporator - #6 hose with male O-Ring end at drier and welded on factory Porsche #6 male push O-Ring firewall fitting.  Includes a High-Side Port mid-line.
[You must be registered and logged in to see this image.]
<#6 Hose Male O-Ring Fitting>                         <Factory Porsche #6 Male Push O-Ring Fitting>

4: Evaporator out to Sanden GM Compressor - #10 hose with male O-Ring end at compressor and welded on factory Porsche #10 male push O-Ring firewall fitting.  Includes a Low-Side Port mid-line.

[You must be registered and logged in to see this image.]
<Firewall Evaporator Connections>                                  <Sanden GM Female O-Ring Ports>

Note: If any of the Forum experts see something wrong with my approach, please feel free to provide correction and/or guidance.

One website that many folks have used to obtain custom built AC lines is Coldhose [You must be registered and logged in to see this link.] in FL.  I investigated the site a bit and if you can identify required lengths, desired end clocking, and required end connections, Coldhose can build custom lines for you.  Unfortunately, the above work list includes custom adaptations using factory Porsche components.  I’m sure with additional communications etc., the Coldhose folks could do this custom work, but I’m going to give my local AC shop a shot first.  Zarin Truck and Automotive [You must be registered and logged in to see this link.]   These guys are very close to me and come very highly recommended by other professionals in the Ohio Valley.  I will be able to bring the car there in the Spring and get a solid estimate.


Next up, Fuel Line modifications…

Most of you already know that the factory fuel lines, both the high pressure feed and vapor return, are steel lines that both come through the wheel well (the passenger side on my 944S) and connect to the factory fuel rail via separate flexible line sections using bubble flare connections. These lines are fully accessible after removing the inner fender.

The HP fuel feed line is 10mm or 3/8” nominal OD steel hard line.  The vapor return line is 8mm or 5/16” nominal OD hard steel line but is not used in the LS conversion.  More on that in a future post,

After removing the Porsche flexible fuel lines to the engine, what is left are bubble flared ends and metric tube nuts.

[You must be registered and logged in to see this image.]
<Fuel and Brake Lines Behind Inner Fender>              <10mm Fuel Line (Foreground)>

I searched the Internet high and low looking for an adapter fitting that would connect the 10mm bubble flare line to -6 AN male end.  Similar adapters are available for 3/16” brake line with inverted (double) flare ends but only to-3 or -4 AN.  NOTHING for bubble flare to -6 AN.  The only thing I could find that was even close, was a replacement fuel line from Pelican Parts that had the female bubble flare connection at one end for the 10mm line and plain hose at the other end…only $95.  NO THANKS!

My next option was to cut off the bubble flare and use a compression fitting adapter to -6 AN.  I found a multitude of adapter fittings from Summit, Earls, Evil, Russel and more, all of which are anodized aircraft quality billet aluminum and use a brass ferrule to make the seal.  As I explored the technical data on each to get the highest quality units, I found that they ALL indicate they’re designed for “hard lines” which they describe as aluminum and copper/zinc alloys.  Exploring product reviews regarding use on “steel” hard lines, industry professionals all say “NO” because the difference in the coefficient of expansion between steel and brass will ultimately lead to a leak.  Also, because the steel tube will not deform to seal by the ferrule like a softer metal would, tightening the fitting sufficiently to provide a lasting seal sometimes breaks the fitting.  

On the other hand, a fair number of DIYers report no problems with leaks on steel and/or SS lines…immediately after installation that is.  I haven’t seen to many reports regarding long term performance.

[You must be registered and logged in to see this image.]
<Typical Aluminum Adapter w/Brass Ferrule>

Call me Old-School but I don’t want to risk any fuel leaks ANYWHERE!  I also don’t trust the “quick-connect” fittings that use the plastic locking clips…especially under the hood where a leak almost guarantees a fire.

My conundrum ended when Kent at TPC sent me links to the proper adapter pieces designed for steel tube fuel lines.  If you’re just starting your conversion and you need all the fuel line modification components, TPC has a complete package you can purchase to get the job done.

On the other hand, if you’re piecing your system together like me and still need steel fuel line adapters, below is the order I placed recently from Discount Hydraulic Hose [You must be registered and logged in to see this link.] in Philadelphia, PA.

[You must be registered and logged in to see this image.]

Total cost came in at $44.27 including Tax and Shipping.

I purchased two (2) adapter sets for the 10mm steel fuel line, one for the front and one for the tank end.  I also purchased an adapter set for the 8mm steel return line to the tank.  The adapters came with a steel washer and O-Ring for straight thread connections but these are not required for a hard line compression fitting connection.

[You must be registered and logged in to see this image.]
<Steel Tube Compression Fitting Adapters to 6-AN Male>
   
To get started, I thought it best to completely map out my proposed fuel line modifications.  It also made sense since it was still below 40 degrees in the garage and I’m recovering from a bug.  

Below is a graphic of my proposed fuel line configuration:
[You must be registered and logged in to see this image.]

And here is the corresponding parts list:
[You must be registered and logged in to see this image.]

Just like the AC diagram, If any of the Forum experts see something wrong with my approach, please feel free to provide correction and/or guidance.

This week it’s supposed to warm up to the mid 40's and hopefully I can get busy putting my plan into play.  

Next up, connecting the fuel line to the engine…

Raymond,

Were you ever able to get your hood to clear the throttle body?

JW1970,

Sorry, no progress in that area just yet. I only need about 1/2 - 3/4 inch to make it happen and I'm hoping I can get that by removing/modifying the under hood reinforcement. Some other folks have successfully done this.

Right now I'm focusing on the fuel lines, heater hoses, and wiring harness as I really want to fire this beast up! Small, time-consuming hurdles at every turn...of course!

When I get to the hood clearance issue, I'll be sure to capture the process in photos.

What type/size throttle body are you running?

JW1970 wrote:What type/size throttle body are you running?

Jantzer Performance, 92mm billet aluminum.

It seems to have a slight upward tilt coming off the FAST intake.

[You must be registered and logged in to see this image.]

Yeah, I can see that now that you pointed it out. It does look a little taller.

I have a Nick Williams 92mm TB on order and may face the same issue as you.

If so, I am considering the throttle body below.


[You must be registered and logged in to see this image.]

That Fast intake and t-body is about 3/4" taller than the stock LS1 intake. The LS1 intake and t-body require some grinding on the top of the t-body and cutting the reinforcement out of the center/front of the hood, and will still rub on hard accel. I have used thicker spacers between the body and crossmember to help get more room for other intakes. TPC spacers are 1/2" thick. I've used 3/4" spacers with no issues.

Hello Forum friends!

I’ve been off the grid for a while because of an unanticipated “work related” assignment and my fuel line installation plans got sidelined.  I also still had some planning to do relative to where exactly I want to route the fuel line on the inner fender.

My plan at this point is for the fuel line to emerge from outside the inner fender through a new front opening (with grommet) and attach the SS fuel line to the front of the passenger side fuel rail.  

This seems simple enough but there are many system connections on in the passenger side engine bay in general and some serious pre-planning is order. The fuel line, AC lines, dryer, heater hoses, battery and starter cables, wiring harness, and cruise control cables, all share this space.

I decided to start with the heater hoses and heater control valve. These parts were all supplied in my TPC conversion kit, including hose clamps.

On my 2002 LS1 water pump, the 5/16” port (red arrow)is the pump outlet feed line to the heater core via the heater control valve, and the 3/4” port (blue arrow) is the pump inlet return line from the heater core via the heater control valve.  

[You must be registered and logged in to see this image.]
<LS Water Pump Inlet / Outlet>                                   <Heater Control Valve Flow Arrow>

The TPC supplied heater control valve is vacuum actuated.  Mine has no brand marking on it whatsoever but is apparently one of the two brands below:
AC Delco 12380318 - $38, Summit Racing
Four Seasons 74781 - $24, Summit Racing

It’s a bit hard to see, but there is a molded arrow on the valve plastic (yellow circle) that identifies the engine/water pump side of the valve.

The heater control valve uses a vacuum solenoid to operate a valve gate that directs coolant flow.  With the vacuum line from the Porsche HVAC control unit connected to the solenoid, and the engine running, constant applied vacuum closes the flow control valve forming a loop, and coolant simply circulates out of and back into the water pump. This is the bypass mode. When the heat is turned on, vacuum is released and the valve closes allowing coolant to flow through to the heater core and then back to the engine.

[You must be registered and logged in to see this image.]
<GM Heater Control Valve Closed                                     <GM Heater Control Valve Open
Vacuum YES – Heat NO>                                                   Vacuum NO – Heat YES>

The HVAC unit vacuum supply line (black) is the upper nipple on the firewall (4). The vacuum supply line for the heater control valve solenoid (orange) comes from HVAC unit and is the lower nipple on the firewall (5).

[You must be registered and logged in to see this image.]
< HVAC Under Dash Unit>                                               < Firewall Heater Vacuum Lines>
(Courtesy of Clark’s Garage)  

My factory HVAC unit vacuum source is a connection to the intake manifold (A) that is managed through an electronic vacuum regulator (E) and a vacuum diaphragm (B).  The vacuum line source for the HVAC unit (4) is connected to the diaphragm nipple (C).  The large nipple (D) coming off the vacuum diaphragm connects to the factory EGR carbon canister and I believe the factory PCV valve through a T-connection in the line.  I’m not positive about the PCV connection because that part of my factory 944S vacuum hose routing decal was worn off!

CORRECTION: After more investigation, the large diaphragm nipple (D) was connected to a T via the short hose, with one line going to the EGR carbon canister and the other going to the fuel tank vent line.
   
[You must be registered and logged in to see this image.]
<Porsche Vacuum Diaphragm and Electronic Regulator>

(B) Evaporative Emissions Control Valve (for Carbon Canister Evacuation)
PN: 035 133 517   39 000 60 620 MHO (VW/Audi unit)

(E) Bosch 040 Carbon Canister Electronic Solenoid Purge Valve
PN: 0 280 142 151
Fuel Tank Breather Valve

Tapping into the wealth of information on this Forum I found the following post from Bob, one of the prominent 948 builders in the business.

H-valve for LS coolant/heat
Hotrodz of Dallas
Fri Sep 30, 2016 10:11 am

“I get vacuum from the back of the intake manifold. Most of them have a port on the back for power brake vacuum. You can reduce this port down to the small vacuum line need for the heater valve.
You need to run a vacuum line from the intake to the Porsche check valve that was original on the car. From there it will go to a tee where one leg of the tee goes to the vacuum reservoir and the other leg of the tee goes to the top port on the firewall. The bottom port on the firewall goes to the heater valve.”

This all makes good sense, but I don’t seem to have the “vacuum reservoir” Bob refers to, and I have some concerns about the performance and reliability of 35-year-old factory control valves.

If someone can enlighten me on this, I would be extremely grateful!!

So…I elected to start the whole process with installation of the two heater hoses so I could determine where I should mount the heater control valve and also determine where the AC lines would eventually fit best.

Normally heater hose installation is not forum worthy, but I ran into a small problem worth mentioning. As you all know, the heater hose ports are close together and there is little room to operate.  After I installed the lower 5/16 in. inlet/feed hose and tightened down the clamp, I then attempted to install the 3/4 in. outlet/return hose.  The hose went on fine, but the clamp is another story.  Unfortunately, I miss-judged where the best location for the clamp screws would be and consequently could not get the return hose clamp on past the inlet hose clamp.  The solution at the end of the day, was to remove both hoses, repositioning the clamps, and for good measure, I reused the factory NORMA clamps because they are a good deal more compact.  You can see in the pic below that the NORMA clamps are considerably narrower.

[You must be registered and logged in to see this image.]
<Replacement vs. NORMA hose clamp>                           <Heater Hose Installation at Firewall>

The next step was to layout the new hose routing and determine optimum cut lengths.  To do this, I first cut the formed 90 degree ends so each hose cleared the frame rail by at least 1/2 inch.  I then connected the hoses to the water pump to see where exactly I could mount the heater control valve.

My plan was to mount the heater control valve to the factory PS fluid reservoir mounting bracket and run the heater hoses forward enough to leave plenty of room for the AC lines coming off the compressor.  It turns out, the 3/4 in. hose is just long enough to make the connection when routed past this bracket.  The 5/16 in. hose is easily a foot longer than needed.

Holding the heater control valve in position, I cut the hoses to fit and used a zip-tie to secure the control valve to the PS reservoir mount.  Next, I drilled a hole in the strut tower for a self-tapping SS bolt and hose clamp to secure the 3/4 in. hose.  A few zip ties later to maintain parallel hoses and the installation was done.  Yay!

[You must be registered and logged in to see this image.]
<Heater Hoses on the Water Pump>                                  <Heater Control Valve Mounted>

[You must be registered and logged in to see this image.]
<Heater Hose Clamp Support>                                           <Final Heater Hose Installation>

Next up, I’ll be working behind the intake manifold to install the oil pressure sending unit adapter and establish a vacuum connection for PCV and the HVAC unit.

[You must be registered and logged in to see this link.]

This is the vacuum reservoir. It is mounted just inboard of the battery. Should be a flat metal tab pointing straight up that the reservoir attaches to.

As far as the carbon cannister purge valve you have there, I usually remove it and use the GM purge valve that plugs in to the intake right behind the throttle body. If your engine harness does not have the connector for the purge valve, then you can attach a small filter to the hose from the cannister and just let it vent to atmosphere. Have never encountered any issues by using the filter.

Hey Bob...

Thanks so much for the vacuum diagram and instruction.  It really points me in the right direction!!

My 944S vacuum line decal is primarily for engine components and has so many lines on it that connect to components I no longer have.   Not worth much!

I did notice the vacuum canister when I was preparing my battery box.  I wasn't sure the role it played but with the vacuum routing diagram you provided, I now know "the rest of the story."

Thanks again for being such a great resource!!

Today I'll check my wiring harness to see if it has the purge valve connection, I think it does but it has been a while since I had it made.  My nephew was very diligent in combining the LS and Porsche wiring connections so I'm optimistic.

I'll document my progress in a separate post.  Getting closer!!

BTW... Last fall I purchased a 0.68 5th gear set from Flying Horse Motorsports. There was a little inventory mix-up and Dimi had to find me a set, but he came thru and I now have in my possession the gear set, gaskets, new rear seal, and case reinforcement plate (from TPC).  

I don't have the LS purge valve. So for the fuel tank vent I deleted the "purge valve" (E) but kept the "control valve" (B) and ran a line to my intake ahead of the MAF. Careful with just sticking a filter on there, it could fill your engine bay and garage with explosive gasoline fumes.

Rich

Rich,

Thanks for the advice!  As I spend more time at the back of the engine dealing with sensors, sending units, ground wires, and vacuum hoses, I'm getting a better idea of where everything is supposed to go....

I should have a pretty decent vacuum line configuration defined this weekend.

One more learning adventure!!

After some solid Forum guidance and a bit more investigation, I have come to the conclusion that the factory vacuum source to the HVAC unit may have been reciprocating vacuum apparently regulated by the EGR system control valve and diaphragm configuration, which simultaneously regulated venting of the fuel tank to the EGR canister.  The vacuum canister in the battery box area provides a vacuum reservoir/buffer for a constant vacuum effect and more efficient HVAC operation.

Regardless of the above, the bypass design of the GM fuel filter/regulator has one fuel inlet from the tank, one fuel outlet to the engine, and a return outlet back to the tank by intercepting the existing fuel tank return line at the back of the car. The fuel return line from the engine bay is no longer used, but the fuel tank vent line up to the engine bay and under the hood does carry fuel vapors and should be managed based on your project application.

Moving forward, I now feel comfortable replacing all of the factory fuel vapor line control components and connecting a direct vacuum line with check-valve from the intake manifold to the HVAC unit and vacuum canister... just as Bob described.  Sorry folks if I've made a "mountain out of a mole hill!"  I just like to fully understand exactly why I'm doing what I'm doing...

I'll post a few pics after I get the lines all connected.

It’s fairly well known that the LS oil pressure and water temperature sensor/sending units are not compatible with the factory Porsche gauges.  Unfortunately for me, this didn’t “click” until after I purchased new LS sending units and installed them as part of my engine build.  Worse yet, I installed the engine before knowing this as well and now the swap just got a bit more difficult!!

I started by purchasing the correct pieces from Kent at TPC:
Water Temp Sending Unit - $36
LS Engine to Porsche 944 dash gauge
VDO A2C59517248-5 (Includes cooper washer)

Oil Pressure Sending Unit – Adapter Kit - $120
    • LS Engine to Porsche 944 dash gauge
       VDO 360-009, 0-80 psi, +/- 6 psi,
    • Auto Meter Brass Metric Adapter #2268, M16 x 1.5 to 1/8” NPT / 27 TPI
       (with copper compression washer)
    • Brass 45-degree elbow – 1/8” NPT (required for clearance)

[You must be registered and logged in to see this image.]
<VDO Temperature Sending Unit>                              <VDO Oil Pressure Sending Unit, TPC Kit>

My 1st obstacle was removing the factory LS oil pressure sending unit.  Not a big deal if you have the proper tool…which I did not.  Amazon Prime to the rescue!  (~$15)

[You must be registered and logged in to see this image.]
<Factory Oil Pressure Sending Unit>                                < Sending Unit Removal Socket>

After vacuuming out any remaining loose sealant threads, I applied Permatex liquid Teflon thread sealant to the Auto Meter metric adapter in conjunction with the cooper crush washer, and tightened it in place using a 7/8” socket to 20 ft-lbs.  The max recommended torque was 25 ft-lbs.

[You must be registered and logged in to see this image.]
< Socket / LS Sending Unit / TPC Swap Kit>             < Torqueing the Metric Adapter to 20 ft-lbs>

Next up was the 45 deg brass elbow.   More liquid Teflon and then several turns until the fitting was tight and most importantly pointing outward.  I used a small crescent wrench to get it done.   I repeated the process with the sending unit itself but only hand tightening as much as possible.  With the Teflon sealant still soft, I could make final adjustments to the overall unit position to provide clearance for the vacuum line to the manifold port. (blue tape)


[You must be registered and logged in to see this image.]
< Brass 45-degree Elbow in Place>                           <VDO Oil Pressure Sending Unit in Place>

Regarding temperature sending unit, I have two sending units I’m planning to use.
1) The factory LS sending unit which feeds the ECM, and
2) the TPC sending unit which feeds the dashboard Porsche gauge.  

As far as I know at this point, this is viable… of course I’m always open to Forum suggestions!

My wiring harness has a sending unit lead for the LS unit on the front of the driver’s side head, so I put my new LS temperature sending unit there.  The corresponding water jacket port on the passenger side head was plugged.  I replaced it with the VDO temperature sending unit.

[You must be registered and logged in to see this image.]
<LS Temperature Sending Unit – DS Front>            <VDO Temperature Sending Unit – PS Rear>

Next up, some wiring harness connections behind the intake and hopefully the fuel rail cross-over line.

The fuel tank vent operates when you fill the gas tank. Presumably, the engine is off so there's no vacuum at the "control switch", so that's closed. The bypass style fuel pressure regulator is not involved as the fuel pump is not running. The air in the empty section of the tank is forced out as the tank fills. The idea is for that air to pass through the charcoal canister, capturing most of the fuel vapors, and out the underside of the car away from the engine. So when you restart the engine bay isn't full of explosive vapors. And then at idle the purge setup slowly draws a little air through the charcoal canister ingesting and burning those vapors gradually.

If you cap the fuel tank vent you'll constantly struggle to fill the tank. Pumps will annoyingly click off on you all the time because the displaced air is trying to escape out the filler neck.

If you stick a filter on the vent line in the engine bay, that filter will catch a ton vapors when you fill the tank. Then as it sits those vapors will slowly escape the filter element into the engine bay and the garage if you park it inside. Or worse, the vapor laden filter is directly above a super hot exhaust manifold. Or it becomes saturated and needs only a spark or super hot exhaust manifold to burst into flames.

Moral of the story, just leave the vent and charcoal canister, rig up a purge system. Stay legal. Stay safe.

The best way to have the purge working, is to make sure your engine harness has the purge valve connector. If it doesn't, then get the connector and 2 wires, and add them in. You can then use a GM purge valve hooked to the intake. Then have your tuner turn on the purge in the ecu.

I have hooked up the vent hose from the cannister straight to the intake without any valve. It works, but my tuner says it was harder to tune because of the varying vapors, So I don't do that anymore.

Bob and Rich,

This is some great information...thank you both!  

I understand now that there is a 3rd line for the fuel tank vent which must remain functional.   The top of the tank is about the only part of the car left that I have not seen.

Here's some pics for the rest of the forum folks that may not be familiar with what we're talking about:

[You must be registered and logged in to see this image.]

So, I'm going to maintain the fuel tank vent line and install a purge valve set-up as recommended.  I checked my wiring harness and could not find any lead for a purge valve.

I would like to go the GM purge valve route so I will be tracking down some new parts next.

For the HVAC vacuum line...

As shown in the pic above, my set-up seems different from the factory diagram in that the orange vacuum line coming out of the bottom firewall port is connected to the vacuum canister and what I thought was a vacuum supply line for the HVAC (the other end has the check valve).  From Clark's HVAC diagram however, and the factory vacuum line diagram supplied by Bob, the bottom port is supposed to be the heater valve vacuum source, and the top port is supposed to be the HVAC vacuum supply line.

I'm pretty sure my heater worked back in 2004 ....but then again maybe not and this could be why!

Well folks,

I got my GM OE Purge Valve today.  Yay!    The unit I purchased was recommended by Bob at Hotrodz of Dallas based on his research and experience.  Thanks Bob!!

Vapor Canister Purge Valve ~$25
GM Part #12597567  AC Delco #214-1680  
GM Parts Direct via Amazon.com

Pigtail - Evap. Canister Vent Valve Solenoid ~$12
Dorman 645-631, Red, 2-way with Leads
Amazon.com

[You must be registered and logged in to see this image.]

Moving forward, I plan to mount the purge valve near a vacuum source off the front of the intake manifold and run a vacuum line back to a T in the fuel vent line.

I also learned that my MS3-Pro ECU can be programmed to manage the valve.

I'll post pics of the final installation....

great work, looks amazing

Thanks Yoshjgg!

I just recently picked up the electrical tools and supplies I need to finish up the electrical work in the engine bay...coil pack connector extensions, wiring harness, and purge valve pig tail connection.

More details on those things and the final HVAC heater control valve hook-up coming soon..

I put some thought into placement of the GM Purge Valve, and the spot that seemed to make the most sense was adjacent the original T-connector to the fuel tank vapor line and charcoal canister.

The obvious mounting location was on the driver’s side inner fender using one of the existing sheet metal bolts that mount a nearby wire junction.  For a mounting bracket, I cut a strip of heavy gauge aluminum sheet that fit tightly into the clip grove on the purge valve.  I drove the bracket into the purge valve mounting slot with a small hammer...it was nice and tight.  Next I drilled a hole in the mounting end, and then gave it a 15-degree twist so the vacuum end nipple was accessible.

After a trip to AutoZone for some vacuum line I was ready. First I connected the short hoses to the purge valve. This included a 4” length of 5/16” hose which fit perfectly inside a 2" length of 15“32" hose, which fit perfectly on the factory T-connector. Installation was simply enough.  I just removed the factory wire junction bracket bolts, cleaned up the attached ground wire connections, sandwiched in my new purge valve mounting bracket, and replaced the bolts.

[You must be registered and logged in to see this image.]
<GM Purge Valve and Hose Assembly>
       
[You must be registered and logged in to see this image.]
<Installed GM Purge Valve>                               <Vacuum Source at Front of Manifold>

I routed a 30” piece of 5/16” vacuum line to the front of my FAST intake manifold and that completed the install.  All that remains is splicing the pig tail into the wiring harness.  

Next up, final HVAC vacuum line connections and installation of an external PCV valve.

This is awesome documentation!

Thank you for the details!