[Jack21]

This Months' Muscle Mustang, and Fast Fords tests 6 sets of heads in a CHP 393W dyno test mule. The Com Cams hydraulic roller cams were a little (in my estimation) on the wild side for a "street" motor, but the top performers (AR, & TFS) were making 525 HP on pump gas at 6400 - 6600 RPM.

RPM's are typically limited to 6000 or so with street valvesprings and hydraulic lifters, flat or roller. And a street cam, you're not making any power over 6000 anyway.

Pushing the engine from 6000 to 7000, reliably, and still making power requires you to go first class on everything in the bottom end.

There are better places to shop than FMS for motors. Someplace you can drive to and discuss your build with the shop owner who builds HP street and race motors for a living. Then drive to to pick up your work-of-art. Then drive back to for further discussion, diagnostics, and repair if there are any problems.