High Riser castings

The high riser castings are unchanged on the intake side - still require porting. The exhaust side is identical to the revised medium riser with a larger squared off exhaust port compared to the older one. The exhaust side of the newer heads has the 16 bolt 428CJ pattern. It also requires different head studs/bolts - now uses 9 "long" ones and a single "short" one in the outer center position.

The cross section of the newer medium riser port is pretty large - might be too large for a street oriented smaller cube engine. It is big enough that the Dove intakes, or factory intakes will not port to fit without welding on the the upper port casting under the valve cover. The new head will, however make very good power on a stroker with no significant port work at all.

Barry Rabotnick
Survivalmotorsports.com