More 72 LT-1 engine questions

[Tony 38901]

I noticed one of my pistons has part numer 1801P STD stamped right on the top. It looks identical to the 3959456. I cannot find any info on this piston anywhere. Help?

I have the LT-1 cam kit part # 12364054. I have a bottle of GM cam pre-lube part numer 1052356. The documentation that the cam came with specifies to use 12345501. Is there a difference between these two cam lubes?

All my old push rods are nice and straight. Do I need to go with new push rods considering I am going from a hydraulic to a solid cam?

Other misc. items I'm changing & would like some opinions on:
I'm going with a thinner .015 rubber coated steel shim head gasket. I estimate this will bring me close to 9.9:1 compression.
I have a set of ARP hex headbolts to bolt my nicely rebuilt 3 angle vavle job/pocket ported heads.
New Cloyes True Roller timing chain set.

[Tony 38901]

one more thing

Is it OK to remove traces of head gasket material on the block using aluminum oxide sandpaper? I would have a shop vac sucking up the debris as I'm sanding.

[Joe Lucia (12484)]

Re: More 72 LT-1 engine questions

Tony-----

I vaguely recall that "1801P" might be an old TRW number or a numbper for another cam manufacturer. This piston may have been replaced somewhere along the line.

The lube you have is an old number for what later became 12364054. It will work just fine.

If your pushrods are straight and there is no discernable wear/damage on the ends, you can reuse them. Hydraulic pushrods for small blocks are the same as those used for solid lifters. The stems of all later GM small block pushrods are hardened, so if you're using guide plates, as all 70-72 LT-1's were originally supplied, you shouldn't have any problem.

I've not used the rubber coated shim type gaskets. I prefer ARP bolts for most critical engine fastners, though, and I always prefer Cloyes True Roller timing sets to all others.

I would not use the sandpaper to clean the deck surface. Instead, use Permatex Gasket Remover. It might take a few applications and scraping between, but this is a far safe method.

[Duke Williams (22045)]

Re: More 72 LT-1 engine questions

Ditto what Joe said.

Look at both the pushrod, rocker arm, and rocker ball wear surfaces. They should be burnished with no evidence of galling or notching. If such is the case they are okay to reuse.

I hope you kept the pushrods, rockers, and balls as "matched sets" as it is best to reinstall them in their original mating positions.

Scrape the block and head surfaces, then use acetone and Scotchbrite pads to remove any remaining organic material. DO NOT USE SANDPAPTER as their is NO WAY to remove all the grit that will fall into the cylinders. Much of it is near microscopic.

As long as the head and block surfaces are flat as measured with a .0015" feeler gage and a machinists bar, there should be no problem with a coated steel shim gasket sealing.

If you don't have the mechanical lifter lash setting document, e-mail me and I will sent it to you.

Duke

[David Morland (42626)]

Re: More 72 LT-1 engine questions

Ditto what duke said regarding sand paper! I've seen a few engines come apart prematurely after very few miles because all the abrasives were not removed before assembly.