I used to have an early Bronco with a NP-540
5-speed tranny behind a twin 3 cyl Buick engine that I towed loads up to 14,000 GVW with just fine. It is a close ratio 4-speed with a granny gear. That makes a great combination. No OD though, so you have to select the correct rear end ratio. I had 3.50 gears with 225x15 Michelin tires.
Ed Pruss
Longmont, CO
