Found a guy locally selling a set of complete zo6 heads.
I might be able to get them $450 for the pair
My questions are whats the differance in these compaired to others and will they work on my 03 4.8 motor ? Seems like a good price if they are trully a zo6 heads. What numbers should be on the heads ??
Sorry new to the lsx motors.

 

I have LS6 heads, and also asked about putting them on a 4.8 liter. They will fit, but will lower your compression ratio, not really sure how much though. Mine are #243 castings. I was going to put in an Ls6 intake also, but everyone says to stick with the stock truck intake (the big ugly).

 

The unmilled LS6 heads (#243 casting) will lower your compression ratio by about half a point. I believe the factory c/r of the 4.8 engines is 9.5:1. The LS 6 heads would put your c/r around 9:1.

Richard

 

all lsx components will interchange on gen 3 truck motors( vortec 4.8and up exc. 8.1 big block)