Quote:
Originally Posted by oldskool
Nope, the '72 400 has a 310hp factor. The 455 is only 315. It would be better. But those 455 heads had press-in studs and no end exhaust manifold bolt holes. And I don't have a set anyhow.
A '75 GP with a 455, factored at 300hp looks pretty good. And they show the 5c heads are legal on it. These heads are almost identical to the 6x heads that I have. And they have screw-in studs and all 6 exhaust bolt holes. 
But, I just noticed that NHRA does not list any accepted replacement piston for the '75-'76 455's. They must be oddballs of some kind--maybe a bevel around the edge, or no valve reliefs. Anyhow, a barely under car at a divisional will most likely not be torn down to check the pistons. And I assume that if somebody requested it, NHRA would probably allow the same pistons they have listed for '70-'74 455's, since there would be no big performance advantage. |
That head doesn't have two ears snapped off?? There are no outer manifold bolts??
Wtf were they thinking? Unless the flange on the header is 1/2" thick or something, how would that not leak?