Looking for some Differential advice

That's a 26.5" tall tire. Yeah, it's gonna be a dog with the highway gears I'm sure it has, but 50 up hill? Sounds like it has some tuning issues, too.
Very likely, thing is, it fires right up, runs around town no problem. It won’t smoke the tires, but it runs great. You’ve seen me go through all the bs with this car over the last year. All of the interior and wiring is done now. Next is the new motor trans and rear end. I just want to drive it for a while I have it. What happened to the site? I’ve been gone for a while