Have seen noted here and a few other places that if you use a carb style intake that it is hampering the potential of what EFI is capable of. So you can't compare a carb to EFI swap using the same intake. So how is the right intake design developed? Have seen everything from huge plenum short runner to little plenum long runners used on EFI engines along with converted carb style manifolds. How much is there to be gained with a "proper" manifold?
Have helped a friend get an MSII running with lots of phone help from Wes Kiser. (thankfully, he was willing to spend a few hours on the phone to help us dumb rednecks). But still uncomfortable with it all.