It's a Comp custom roller grind. I run NA with Nitrous. I have the same cam in my 4.1 now. It's .526 lift with 1.65 rockers on a 108 LSA with 228 intake and 230 exhaust @.050 lift. Same cam as an old Kenne-Bell Mk II R cam. Pulls hard in the mid range on a 4.1.