Isn't your hemi engine a individual runner design? Not siamesed intakes.
If that is the case, a manifold with equal length runners to the flange of carb base is the best option. The are formula's around to calculate the lenght of runners for picked RPM running designs. The problem with the inline engine is the length that all must be stretched out to reach the middle. It is hard to get equal lengths. It seems to me a runner length of around 15" is really good for optimun tq around 5k rpm, can't remember the cross section size. Shorter runners will move the peak tq higher in rpm. Tom
