I bought a 95 F-150 reg cab, XL, 4x4, manual, 300-6, long bed, dual tanks awhile back. Never got great mileage, think it was about 14/15 mpg when I got it, now it gets 12/13. I changed the 3.08 to 3.55, 31” tires, one ton suspension, and did a ZF-5 swap. Not at all a fast truck, but it will drag anything at roughly the same speed and fuel economy as it moves a round empty. Totally sold on these trucks and engines. I haven’t found anything to hook it to that it couldn’t move. That includes pulling a couple 30-40’ tall trees out by the roots.
Looked it up awhile back and the 300 has roughly a 4” bore for each piston which travels roughly 4” and is designed so that one piston is always on the power stroke which is where the incredible torque comes from, unlike a V motor that may have a dead spot to each cycle and relies on rotational force and physics to make up for things. It’s a huge tank of a motor and about as indestructible. Also sounds suspiciously like an old farm tractor, lol