HELP - Correct LS1 Head Gasket ID?

[GeoffP]

How do I identify which head gaskets to order for my LS1 build? Pace Performance lists two different MLS part numbers for LS1's - one is for 97-2001 and the other is for 2001-2004. I don't see much difference between the picture's on Pace's website:

http://paceperformance.com/c-147043-...nder-head.html



Can anyone help me to pick the correct one?

Thanks!

[daytonayellaz]

What year is the motor you are building?

[GeoffP]

That's a good question - it's a hodge podge of parts. I know the block is a pre-04 block (it uses the LONG head bolts) and the heads are off of an '00 WS6 Trans Am. The block is actually a cast iron 5.3 block bored to LS1 standard bore size. I think it's from a '99 or '00 truck but am not sure. I have an '04 4.8/5.3 block that I can compare it to to see if there are any physical differences (besides the bore size) if it's important to get the right head gaskets. I have looked before and haven't really noticed any difference other than the head bolt length.

[Mike Norris]

The 97-2000 gaskets used a fibre gasket, for lack of a better description, and had to be used with the older heads (97-98 perimeter bolt valve cover??) due to a notch in the head gasket sealing area that a newer MLS gasket will not seal. The bore sizes for both are the same.

For the newer block and 00 LS1 heads the 2001 and up gaskets should work fine.

Mike Norris

[GeoffP]

Thanks - the heads are definitely center bolt. I really am not sure how to check the year of the block...assuming the later gasket will work? BTW, how do you clean the OE gasket gunk off the heads without messing them up? Spray gasket remover?

[Kaarle]

http://karlperformance.com/c/Cylinder-Heads/2491

This website gives you more clarification about head gaskets