Speedmaster/Pro comp Heads..

I can tell you after building a LOT of these, they need a serious hand blend from the CNC porting, a .005" mill to make them flat and true and possibly a few guides. Im not sure on the valve job they have done, but im sure its not the 5 angle one that we do plus the back-cut on the intake.

The Procomp springs are right out of China and they would be the first to go if you are running a good cam with a lot of velocity.

Also pay close attention to the web between the intake ports right under the valve cover bolt, the CNC breaks thru at this spot, same with the RPM heads.

We get ours bare and build them from the ground up and have made over 600HP with them.