Thanks a lot. That is very helpful. Yea I was thinking a size up but using desktopdyno to try to get an estimate using the headflow date and trying to enter everything as accurate as I cam then 254 seems to work out real well with the powerband peaking a little before 6500 and the peak torque looking like its in a great area for the 3500 stall converter.
Looking at Hughes 260/[email protected] solid. Since I plan on running the single plane that is coming out for those heads it might be worth going a bit bigger on the cam then the 254/[email protected].
It will be in a 72 Duster with 4.30 and 27" tire with a 3500 Hughes 10inch.