What kind of differential do I need for towing?
Chevy Van G20, 305 engine, 3 speed transmission w/ overdrive. Does fine on flat trips but mountains it slows to 25 mph towing a pop-up camper. Springs handle the load just fine. Looked into differentials and saw positronic ratings from 28 to 33. What am I looking for? Higher or lower? What do these numbers mean?
first thing, ditch the 305 and get a 350. you will be much happier with the truck after that. the rear end, you want a lower ratio for better torque. a 373 or 411 would be a better ratio when you are towing.