Jim, when you get my book look up the miscellaneous testing chapter and you will see that I tested port mismatches in both directions, bigger intake ports going to smaller head ports, and smaller intake ports going into bigger head ports. For the engines I tested, around the 400-500 HP range, there was no differences between them. In other words, low riser manifolds on medium riser heads gave the same results as medium riser manifolds to low riser heads. The port mismatch you are considering is not a problem.
I think for the most part port mismatch is overrated as a consideration for an engine in the 500 HP power range. I'd be concerned at the 600+ HP level, but at 500 and below the engine won't really know the difference - Jay