Mods to motor are TSP 228R-112, LS6 intake, LT headers, P&P TB, and UD pulley!!!! It has the stock 853's and some 28# injectors also. I want around a 11:1 comp and i have some 243's sitting in a box, what setup would you do to get that goal and would these gain me 25rwhp since i have a nice size cam ????

 

Mill the nead some and run a .040 gasket. The head swap and compression bump might get you in the 20HP gain area give or take some.

 

what about milling .015 and using stock gaskets

 

You'll get better quench (= less detonation) if you leave the heads unmilled and run a thinner gasket.