I ran this cam in a 440 six pack back in the early 80's ,stock cast pistons, stock 906 heads, ran Direct Connection springs,retainers, 1.86 installed height, 100 lbs closed and 300 lbs open with stock rockers which were more like 1.42 which kept it closer to legal lift. Ran it 2 seasons, ran 11.80's 3600 lb Super Bee, Stuck it in a tubbed out 3000 lb. Duster,same trans and converter, only TM7 and 750 Holley and went 11.00 in good air,11.30's in the heat, bracket raced it for a couple years. Great Cam. Piston to valve clearance is critical. I know a couple guys who unintentually put their own valve reliefs in their pistons