Stage V casting number

stage 5 head is basically a factory 452head with slightly revised ports and more material around the intake port to allow for more porting. performance level is only slightly better than a factory 452 casting to a stock head and doesnt offer much more power potential.unless you want a new casting or class rules require them.porting will offer lil improvement.the additional material will require the use of special intake rocker arms with additional pushrod offset to move the pushrod away from the port wall, same as the stage 4s 92cc chambers.wouldnt pay a lot for them.