I am thinking of buying LS6 heads and maybe getting them milled. Would love to get the cnc'ed ones but money is to tight. Figure i can grab a set for $500 and send them to my local shop and get them milled for another $100 to bump the compression. What kinda gain do you guys think I will get on on a 04 GTO that is otherwise stock except for just an LPE intake?

 

20-30whp

 

I think 20-30 is a safe assumption. Probably closer to 20 than 30 though.

 

Just found out a guy I know is selling LPE 241 heads. The heads are cnc'ed and milled .055. Would this make more power than the milled 243 heads?

 

I will wait for others to chime in, but milled that much I think is going to yield a very high CR

 

I was looking for around 11:1 CR, but I was searching around and am seeing that there might be problems lining up the intake manifold when they are milled that much. I don't know much about milling heads and the head gaskets, if anyone has any ideas on these heads it would be a great help.