I have searched and I see the l92 heads have 71cc chambers. Do the ls3 heads have the same 71cc chambers? Im looking to see what my head options will be with a stock lq4 short block. Is there a difference in push rod length between the ls3 or l92 heads and the ls1/ls6 heads?

 

The blueprint for the L92 head shows 68.4cc +-1cc

My heads came out to about 69cc when new.

 

It looks like you did the same thing as what Im wanting to do. I want to use l92 heads on my stock lq4 but Im worried compression would be too low. How do you like yours and how much did you mill the heads?

 

My L92's came out at just barely under 71 cc's bone stock. Just a reference.

 

L92s on an LQ4 came out to be 9.14:1 on the engine I measured.

 

Mine
62cc chamber
pistons .010 above deck
pistons 6.7cc dish
head gasket .052 - 4.065 L92 GM MLS
cylinder 4.00 bore

10.62 CR

 

Mine measured 68cc with a .005 cleanup mill. Stock size valves.