4spd v 4spd O/D

How much highway driving are you planning on doing? A torquey motor will handle the gear spread on the OD fine, but if you have a bigger cam it will not work as well. The OD will work better with at least a 3.23 rear, preferrably 3.55 or bigger. If you plan on going to the track much, you would be happier with the regular four speed.