The port mismatch isn't really any big deal. Much to do about nothing is made over port matching. Chrysler sold a rectangular port dual plane intake for the oval port W2 heads for years. Not many people wanted it because of the mismatch but Larry Shephard (MP engineer) swore up and down it didn't make a difference. I've seen magazine articles where they tested unmatched ports against matched ports and found no difference. The performance gains came mainly in the bowl and the cut leading into the valve seat.