I have a 04 GTO and i did heads and cam. I have the stock 241 heads and stock cam? Would this be a postive if i put these in my 2004 Denali? If so what could i gain from them. What would it do to my compresion? The heads and cam only have 6000 miles on them!

 

Anybody? Someone has to know something?

 

Putting the LS1 heads is a lateral move unless you mill them at least .045" to raise the compression to at least what the stock 5.3l has. You'll get a airflow benefit with the LS1 heads but a large compression loss if used un milled. Furthermore you will need to use a LS1 head gasket (larger bore diameter) to fit the larger chamber width. This makes more compression ratio loss.
IMO your way ahead modding your stock 5.3l heads because the compression ratio can be increased some without a lot of head milling. Largeer valves and some minor porting will also help make a difference.
Good luck,

Richard

 

It has the 6.0 LQ4 in it. The has are the 317 casting's.

 

you would be better off milling the 317 heads and getting a different cam..swapping the ls1 cam in would not be worth the time

 

I believe the 317s are a better head than a 241. I wouldn't bother the hassle of doing such a mild setup. It would be worth the time and hassle of doing it.

 

Stick with the 317's. They have more performance than the LS1's. Some milling would build up more compression and that would help the torque across the rpm range. Of course once the heads are off you could have the ehads ported some and that would also really help with power.

Richard