How to swap over to a LS6 PCV system

Here's the text article I wrote, I've got a ton of pictures, I'll post those shortly...

LS1 to LS6 PCV Conversion


Tools needed - 8mm, 10mm, 13mm, 22mm sockets
- Flathead screwdriver
- Air powered cut off tool
- Dremel with grinding wheel and cut off wheels
- Shop rags
- Saftey googles

Parts - 2001+ LS6 Engine Valley Cover (GMPN 12568002)
- 1 Valve Cover plug (GMPN 12568011)
- 10 inches of 5/16” ID rubber fuel line
- 5/16” vacuum cap
- High Temp silicone rtv

Note: You must have the 2001+ style coolant vent tube as well for the LS6 valley cover to fit. All 2001+ LS1’s will have this and any LS1 that has been upgraded to the LS6 intake manifold and pipes will also have this.

Note: I don’t think my car had this and I managed to bend the coolant vent tube to make it work.

1. Remove your intake/MAF
2. Disconnect the sensor plugs from the throttle body and pull off the coolant lines going to the bottom of the throttle body. Now disconnect the throttle cable.
3. If you have a pre 2001 F body motor with an EGR system, unbolt the EGR pipe from the top front of the intake manifold and carefully bend it a little out of the way so you can remove the intake manifold.
4. Disconnect eash wire plug going to each of the 8 fuel injectors. You need to push the shiny metal clip towards the center of the intake manifold and lift up on the plug.
5. On my car there was a wiring connection on the back of the intake manifold and 1 vacuum line to disconnect.
6. Disconnect the rubber hose on the passenger side going to the throttle body.
7. Disconnect the red plastic connector for the fuel EVAP on the drivers side of the intake manifold.
8. Disconnect the wiring plug and two small vacuum hoses on the drivers rear side of the intake manifold if you have the smog pump.
9. Using a 10mm deep socket, unbolt the PCV grounding strap on the passenger front head. It’s a nut on a stud and the nut is a captive nut.
10. Unscrew the test port on the rear passenger side of the fuel rail and release the pressure. Put rags underneath first to catch the fuel.
11. Now unscrew the clamp and pull the fuel line from the rail. Put lots of rags down, my car had a bunch of fuel in the rail still. Cap the fuel rail port with a 5/16” cap so it won’t dribble fuel all over the damn place.
12. Now unbolt the 10 8mm bolts that go into the top of the manifold. Check to make sure you have everything disconnected from the manifold and lift it up and out of the engine bay. If you still have cruise control just lift up the cruise control cable and pass the intake manifold underneath it.
13. Remove the 2 10mm studs up front and 2 10mm bolts in the rear to remove the throttle body coolant hoses. Expect coolant to come out of all 4 ports.
14. Clean up the surfaces. Now you can see the engine valley cover.
15. Seal up the 8 intake ports on the heads with tape, rags, etc.
16. Pry up the two black round covers that sit on top of the knock sensors. Mine were rtv’d done into place.
17. Using your fingers, or carefully using a set of pliers, squeeze the knock sensor wiring harness plug and remove it.
18. Unbolt the knock sensors with a 22mm socket. It doesn’t matter where they go, so don’t worry about getting them mixed up.
19. Using a 10mm socket, remove the 10 bolts that are holding the LS1 valley cover into place.
20. Pry up the valley cover with a flathead screwdriver. Make sure the gasket came off too. If not, pry it off with the screwdriver as well. Clean up the mating surface with a flat razor blade.
21. Ok, on pretty much ALL the LS1’s there’s this little aluminum block on the passenger side front of the valley that interferes with the LS6 breather system that’s attached to the underside of the LS6 valley cover. You need to cut this thing down, pretty much taking a pie slice out of it.
22. Thoroughly cover the entire area with rags, you don’t want to get any metal shavings down inside the motor. I stuffed paper towels into the two cam openings, then covered everything with rags, then duct taped the rags into place.
23. Mark ¾” of an inch down on the aluminum block. This is approximately the same place as the first casting line on the block.
24. Using a cut off wheel, slice into the block where your line is. Then from the top of the block, pie slice it out.
25. Now use the dremel and grinding wheel to smooth over your cut. How far back you go isn’t that important as it’s the wall closest to the center of the engine that causes the conflict with the LS6 valley cover.
26. Carefully remove all the rags and towels, wipe up any debris etc.
27. Lay the new gasket down into place. Lay the LS6 valley cover into place. Put all 10 bolts in finger tight. Once they’re all in, tighten them down to 18 ft/lbs.
28. Hand thread the knock sensors into place. Torque them down to 11 ft/lbs.
29. Here’s where I had fun with that coolant pipe thing. It interferes with the brass pipe coming out of the passenger side front of the LS6 valley cover. I just took a set of channel locks and carefully bent it down, then up and around the PCV pipe. Replace the two 10mm studs up front and rear 10mm bolts. Torque down to snug.
30. Remove the LS1 PCV hose from the drivers side rear head. Throw away the entire tube. Plug the hole with the grommet you got, GMPN 12568011.
31. On the rear passenger side valve cover there is a brass fitting with a rubber hose attached. Remove that and cap it with the 5/16” cap, I used the red one that came on my LS6 valley cover.
32. Remove the entire LS1 PCV hose arrangement and throw it away.
33. You’re done with the LS6 PCV valley cover installation. Time to reinstall the intake manifold, R&R is the reverse!
34. Connect everything, yadda, yadda, yadda.
35. Now scavenge your PCV valve from the old LS1 hoses. Attach your 5/16” fuel line to one end. Put that onto the brass hose coming out of the passenger front side of the LS6 valley cover.
36. Now push the PCV valve into the male attachment on the front passenger side of the intake manifold.

You’re done!