yeah,, i was thinking it was 3/4 inch longer, maybe i had the victor head in my mind or something,, i make a max wedge 2.700x1.400 so like you said about 30 cc's

i just did another set of 440-1 heads using a 2.250 valve on a 4.380 bore using indy's cnc casting which has a very small port in it so you can do what you want, at .400 they flowed 292, at .600 they flowed 359, 375 at .700 and 381 at .800.. the exh flowed 211 at .400, 242 at .500, 263 at .600, 279 at .700, 291 at .800,, 311 with a tube on it at .800.


im sure the chapman head has a little better throttle response, the port is raised up some if i remember right,, having to use a rb manifold on a b engine,, at 2500rpm it might have better throttle response but up at 4000 or so im sure it doesnt matter too much compared to an indy head, once you put a 4.15 or bigger stroke in it. ill bet that you build two engines comparably and the difference in torque curves wont be more than a few % different from the chapman to the indy.

with chrysler stroker motors the base thought of having a 200 cc intake runner like a stock head goes out the window. a 300 cc port is not huge for a 4.15 or 4.25 stroke,, for drag racing,, not pulling out tree stumps