427 cast iron headers99

[tomsfe64]

I'm building a 427 with iron high riser heads and have a nice set of original cast iron headers. Does anyone know of any dyno comparisons of a 427 with and without iron headers?  In other words how much hp loss would they possibly give.

[Heo]

Its in jays book dont remember the exakt
Numbers but not Much

[69Cobra]

At least 50hp

[jayb]

Depends on your combination.  On my 425HP 428CJ dyno mule, the long 427 cast iron headers made more peak HP than any of the steel tube headers, although the Hookers were very close. On my 500 HP 390 stroker dyno mule, the 427 cast iron headers were down about 15 Hp from the best steel tube headers.  My guess is that the more power you are going to make, the more the cast iron headers will hurt you.