Wheel and tire suggestions for an early '80s D150

Easiest way to shop for wheels I know, is Summits website.
Check out Aero wheels, and Basset. Wide steel Nascar style wheels are still reasonably priced, imo.
And there are hundreds ,if not thousands of wheel styles for 5 on 4 1/2!
Tire size recommendations depend ENTIRELY on wheel size and width chosen, and backspace available.
You could learn what might work, by trying the 275s on the front, and see if they clear