mamead

iTrader: (3)

I've picked out what I need for the rest of my head swap. However, I can't figure out if I need the older ls1 head gaskets (part number 12498543) or the newer (part number 12498544).

This is going on an ls1 in a 98 trans-am. I am running a tsp 228r cam with .588 lift. My heads are ls6 cnc ported and milled to 60.5 cc combustion chambers. I'm trying to determine the proper gasket thickness to acheive the correct compression and quench. The older gasket measures .051 compressed and would give me 11.2:1 compression. The newer gasket is .057-.059 and would give me closer to 11.1:1 compression. Not huge differences but I read that normally a quench of .040 is a good number to shoot for. I haven't measured how far the cylinders come out of the block but is this something I putting too much thought into this? Which would you recomend?

Thanks,
Matt

mamead

iTrader: (3)

In the dimensions section here it says that stock the piston rises .008 above the block, so that gives .043 quench for the graphite and .049-.051 quench for the mls right? Does piston deck height vary considerably between engines and need to be measured for each engine or is the .008 normal?

Sales2@Texas-speed

iTrader: (5)

I would take the MLS gasket over the graphite for your build. I just have more confidence in that gasket's performance over the graphite due to past experiences. Piston to deck height does vary a bit, but not .010" or more.