I have a set of Ls1 heads from a 5.3L truck. These heads have a 61.5cc combustion chamber which will yeild aprox. 10.9:1 CR on a stock ls1, but if they are milled .030" it'll yeild 11.5:1 compression. They have 200 cc Intake ports/ 70 cc exhaust ports. standard w/ a 1.89/1.55 valve size it is reccomened that you upgrade to a larger valve size to get the most performance out of these cylinder heads.

Make me an offer, not trying to get rich here just wanna get them out of my garage.

Thanks,
Nick

 

ttt....