Dan,
If you could make a gradual taper from the manifold to the head with some epoxy you could have a tapering effect which could in the speed of the air and fuel. Any increase in air velocity in the intake port would help as long as didn't go up past 368 ft per second for the rpm range wink that you wanted to achieve. A lot of head porting guru's have a hard time achieving this port velocity.
kojac... wink