The above test used a Hydraulic Roller Cam 236/242 @ .050 and a RPM Airgap Manifold
The test below used two flat tappet hydraulic cams, the RPM Airgap Manifold and a Victor Jr.
The results reveal stepping up to the Victor Jr manifold made 17bhp more but lost 15ft/lbs torque, this is seen on most similar type tests.
The cam change of 10 degrees more duration @ .050 made 30bhp (518bhp) more,
torque was down 20ft/lbs @ 3000rpm and recover at 5000rpm
Using this data we can expect the motor above making 530bhp to achieve 560bhp plus with a Victor Jr and 240 In. dur. @.050 cam.
Another option to hang on to torque but make the bigger BHP numbers is an EXTRUDE HONED RPM Manifold, expect to pay $650 for one of these manifolds.
The old heads made 33bhp improvement over stock heads.
The new heads make 30bhp more than the old heads.
Raising the Bar in Performance Yet Again