Folks,
One should realize a few points in a cylinder head discussion of NHRA stock eliminator head and manifold components.
"trust but verify" is a good methodology to follow.
1) The rule book might state one thing but in practice the "passed tech" cylinder heads are quite another and many examples of ported/reshaped and covered up have passed with abandon. That includes manifolds. It is sometimes a discretionary call as it states in the rulebook. Methinks that there was (is) at least one lawsuit that reflects same.
2) Cylinder head rules indicate that the valve job is "legal" all the way down to the valve guide. This area can be very creatively used by something like a single point cutter that can re-contour the area described. Other methods can also be used.
3) Starting off with primo castings is the best beginning, but not totally necessary if one goes the route mentioned in 1) above.
Regards to All that like this kind of stuff,
HB2
Dissident