85 5.3 swap

I started a thread in the 4.8/5.3 section but this section is more fitting. I bought this car for a great price, it sat for over 20 years because of a coolant leak. After I got it and ran the numbers it didn’t make sense to me to keep the original engine.

I’ve pulled the original engine, cleaned and sprayed the engine bay. I got a later model rack and converted it to manual. Fitted a tilton balance bar to the brake pedal for a dual MC. Got a griffin radiator that I’ll have to remove the filler neck to fit in place of the original. I got a fuse/relay panel for the engine and I’m adding relays for the headlights and fog lights.

I’m getting a 5.3 from an 03 1500 with DBW. I am going to convert it to DBC. I have a 2 piece bellhousing, s10 slave cylinder, C5 flywheel, and a Dodge D150 clutch kit. The clutch bolts up to the flywheel after drilling new holes for the dowels. I have a local machinist making the adapter plate and pilot bearing adapter.

I am making the motor mounts myself. Is it a bad idea to use the plans from this site to make the mounts from? For the exhaust I am going to make my own headers most likely. I’d like to explore some manifold options but there are no success stories yet.

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Some pictures

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More pictures

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More pictures

Donor truck

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watching with great interest. Im i nthe process of finishing up on my first build. i have an 85.5 waiting for another swap. either 5.3 or 07k.
nice progress BTW.

Thanks! I’m trying to do as much as I possibly can to save some money. I’m picking up my torque tube adapter and pilot bearing adapter tomorrow. I actually got 2 sets made, one for me and one for my dad. I got the engine pulled, somewhat cleaned up. I’m going to modify the stock oil pan to match the milodon, and I will notch it for the steering rack. Got the radiator mounted,I had a few broken exhaust manifold bolts also.

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You have come to the right place for all the information you seek on fabrication of your motor mounts and headers. Dig around this site (do an advanced search) and you will find diagrams and measurements to make just about all of the conversion parts you will need. Be aware that most of these posts are from way back when LS conversions were relatively new and the aftermarket had not started providing these parts. The new items that you can buy may be improved over some of the original designs.
Greg Sloan wrote a 944 conversion manual years ago that has been superseded by the information in this forum.
A popular header conversion is modifying a Hooker block hugger header to fit the 944. I think the part number is 2312 or something like that. The passenger side fits perfectly but you have to cut and modify the driver's side. It's not that hard to do if you have good welding skills. The instructions on how to do it are in this forum. I have a set of those modified headers on my car and they work OK but they make any service on the driver's side very difficult if you use a hydro-boost brake booster. I plan on sending the money for a new set of headers this winter. I agree that they are painfully expensive.
Good luck, Gil

Made some good progress. Engine is in, headers are tacked up ready to finish weld, dual master cylinders finished and working, drive by wire pedal switch fitted to work with stock floor mounted pedal.

I made my own motor mounts, and poured the polyurethane in them. It was easier than trying to fit a bushing. I discovered that this oil pan works in the car, but I had to put 2 small dents in it to clear the steering rack. I did modify the original but I was fighting welding to the dirty aluminum and got fed up with it.

Put a cowl scoop on it (not for everyone, but it’s not everyone’s car lol) that will go well with theme when I get around to spraying the car. Truck intake didn’t clear and a Holley sniper didn’t clear, so I scored a LS6 off of eBay for it. I’ve played with the bin file in Tuner Pro RT and am pretty sure I’ve gotten the file ready to write back onto the PCM.

This is my first time making headers. They are not equal length I know. I am just happy they go in and out of the car. I used 1.75” 16 ga stainless.

Oil Pan,
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Your swap looks good! Looking forward to more details as you make progress. Thanks

cool progress, subscribed

tonyorlo wrote:

Put a cowl scoop on it (not for everyone, but it’s not everyone’s car lol) that will go well with theme when I get around to spraying the car. Truck intake didn’t clear and a Holley sniper didn’t clear, so I scored a LS6 off of eBay for it.

so, the truck intake didn't fit under the cowl piece? does it fit with it flipped the other way around, with the opening to the front of the car? thinking if there is a way to use the truck intake without having to change it if needed. lol. trying to save money. but i do have friends in the body shop/working business that can do fiberglass work where needed.

but this looks really awesome. i love a good cowl hood and havent seen any aftermarket ones! i hope it goes fairly smoothly for your build.

Hey,
The truck intake didn’t fit under the cowl scoop. My engine may sit a tad higher than most because I made my own motor mounts. I used a Jegs steel oil pan for a 55-57 Chevy with an LS and only had to put a few small dents in it. I played around with modifying the original oil pan, but it was just too much of a fight trying to weld to the dirty aluminum for myself.

So I’ve been driving the car daily for 2 months now. I don’t think I ever came back and really talked about what I used and how I did everything. I don’t have many good pictures of it currently.

I made my own SS headers, and motor mounts
Used a Jegs 55-57 LS steel oil pan
Dual 2.5” SS exhaust with Pypes M80s
Delco Corvette flywheel
PP and clutch disc for a 89 Dodge D150
C5 Release bearing
Wilwood 7/8 Clutch MC
Griffin Rad with the filler neck welded up
Single 14”(?) summit puller fan no shroud
Wilwood 7/8 brake MC
Volvo 4 piston calipers on all 4 corners
Front coil over conversion with 350lb springs
Manual steering rack
Manual windows
C5 Vette seats

There’s a ton of stuff I’m leaving out. I wanted to do this on the cheap, just to see if I could. After completing it, I could of done a lot of things differently and saved a lot of cash. I had to learn the hard way I guess? I’m currently trying to make the interior a little more comfortable to be in.

Sorry for the first batch of pictures, hit insert a few too many times.

Also, I used a wiper motor from a MK 3 golf. $25 new from Amazon. Just had to change the wire connector and make a shim for the wiper. I can’t believe what used 944 motors cost.

The wiring is a nightmare on these cars, everything is super fragile, and corrodes very easily. I have everything working good now, but a lot of little things really fought me. Just trying to ring out wires to verify continuity was a challenge at times. I plan to build another 5.3 for this car and spray it nautical blue late next year. I may even do the 6 speed Audi transaxle
Swap. When I do that I am going to gut it and re wire it using a universal kit. The switches are very similar to the ones on my Karmann Ghia that has an American Autowire kit that went in pretty easily.

I just can’t believe how quick the car is. The engine has 254k miles and could probably use a freshening up, but the weight must be the reason it’s so quick.

Kudos for your ingenuity and no nonsense approach!!

True hot rodding indeed.

Thanks Raymond!

I really hate driving daily without a radio, so I used some aluminum to make door panels. Got some pull straps coming, and I need to finish covering the original door panel tops to get them on the doors. The center console in the car burst in pieces the second I looked at it, so I used some parts from it and fiberglassed a new one. Added some much needed cup holders too.

I used some cheap contact cement from advance auto, I knew better. Nothing is staying on, for now it works but when I eventually re do the interior I will use better cement and use dye to match all the vinyl.

It’s got 5.25” kicker KS series components, and a JBL GTR-104 amp in the center console. The amp is Bluetooth, so no need for a receiver. It’s got a little controller that I put in the console, but it really doesn’t do much. Got new rocker switches for the fog lights and the blower. Currently they are not hooked up, I added a relay and fuse in the new panel for the fog lights, I just didn’t want to try and re use the factory wiring for this. For the blower I plan to just have a on/off with high speed only. I only need it for defrost and to get the chill out of the car on those single digit mornings.

I am thinking really hard about putting the battery in the back, and moving the PCM in its place. I’m not a fan of having it under the dash.

Don’t give me too much crap for the pictures. Keep in mind it was a $600 car that I use for a daily beater! [You must be registered and logged in to see this image.]