Awesome truck! I want to do an F150 BHW swap. The BHW in stock form is fairly close to the 4.9L I6 in output. 136hp vs. 145, 247tq vs 250. And it probably weighs half as much, and the BHW even with a mild tune would be much more than the 4.9L. Since all similar Ford trucks and vans used the same Mazda R5 manual box, and someone already makes an adapter for either the Vulcan Rangers or the Cologne Rangers, I'd just need to find one of those gearboxes to use. Probably have to cut a link out of the F-truck's front springs, though.
My dad has a '99 Cologne Ranger 4x4, regular cab, long bed, manual, and it struggles to get past 15 mpg. It has the factory off road package with the big 16" tires and the lower ratio locking rear end. It is a beast in snow and off road, but boy it empties that [rather small] fuel tank in a hurry.