Would these tires work?

[beck-529]

Sorry if this has been answered before. I’m kind of new at the big trucks.

I want to make a C50 into a 70 mph truck. That doesn’t work well with the stock tires. Would 275/65R20 tires work on these trucks? If so I expect a tube would be needed in them?

http://www.tirerack.com/tires/tires....160508150658:s

These tires are 34” in diameter compared to the over 40” stock tires. I would install an overdrive transmission. Gearing would still be a problem. What was the fastest gear ratio available and how rare was it?

My truck would be used to pull an enclosed trailer. It wouldn’t have much of a weight load. I am looking at lowering the truck so the tires wouldn’t look too tiny in the front wheel opening.