[Rockhead400]

Dude, I am running these 16 heads in my 67GTO with a mild performance 425 hp 1970 ponitac 400 engine bored to 412 (60 over). I did mill them down some to bump compression to 10.75 using pump gas premium. I did media blasting, new double springs, but used stock rockers and I did no porting. I was amazed that these 72cc heads do so well with no porting, rocker roller. Stock flat type forged speed pro pistons were used with stock rods and stock crank. A mild crane 226/233 cam with.468 lift was used , but dont quote me on the nos. Hooker headers coated, flowmasters with turn downs, edelbrock performer rpm manifold with Edelbrock 750 was used. All in a a pretty simple set up with amazing results. Ample power for street abuse and fun. Of course everything was new for the rebuild, bearings, push rods, etc. Balanced assembly, crank turned to 2/10000. My point is these heads are great for street use and can use pump gas. I wish I had paid the extra for porting. Ill do that next.