This cam has outperformed any cam we have tested it against to date, from idle to 4,200 rpm. It is also the largest drop-in cam that we sell.Use with 62mm or larger single turbos or larger twins. Install intake on a 99 centerline, performance springs and pushrods are recommended. If you have had your head or block surfaced, you need to verify piston to valve clearance.For it to be "drop in" on a 12v you will need no more than .018" piston protrusion and at least .055" valve face depth with a standard head gasket and a 99 intake centerline. On a 24v you will need no more than .018" piston protrusion and at least .038" valve face depth with a standard gasket. If you do not meet the minimum requirements for piston to valve clearance, don't worry, you can still run an oversize headgasket or cut valve reliefs.