I have a 11.1 cmpression forged 347 with ls1 stage 2 heads that were milled wanting to lower compression to run a turbo on car with out having to change pistons. I have wiseco flat-top piston with valve relief will changing to a 6.0 cylinder help me reach a lower compression.

 

Are you asking if changing to 6.0 heads will lower your compression? If so, then yes, they will.

 

as long as ur pistons wouldnt increase ur compression if u were stock, (i.e. if u put on stock heads with ur pistons ur comp would be stock, 10.1) then with the 6.0l heads u should be able to get it around 9.6-9.5