Total Engine Airflow S2 LS1 head's: 2.02"/1.575" stainless Ferrea valves,Comp Cams 987 Dual spring's with titainium retainer's,Fully CNC Ported intake runners,exhaust runner's, and CNC shaped combustion chamber's,Competition 3 angle valve job,comp lock's and valve guide seal's..head's milled .001 for clean up..these are 5.3 liter head's and have a 63cc chamber..on a stock LS1 it will bring compression to 10.8:1..awesome head's..flowed 303 cfm @.600 intake and 260 cfm @.600 exhaust w/ pipe..$1,200.00 shipped to your door!!

Carter