Originally Posted by B3422W5
Originally Posted by 67autocross
Pro Maxx must have sold out of them, a local shop has a 408 going on the dyno in the next few weeks with them and are shooting for 600hp. The heads look good and CNC work is nice.


Any ported aluminum replacement head better make 600 on a flattop shortblock with some squeeze
Even with a healthy flat tappet.


On our local Dyno I don’t think I know of a pump gas small block that has gone over 600hp unless it had some of the moved push rod W2 or Indy heads on ...I’m assuming if this one can do it with the pro max heads the trick flows should be around the same.

A new iron curtain drawn across the 49th parallel