What size tires and wheels go on my truck?

I have a 1975 Ford Courier and I can't read the tire size on the truck. I'm trying to buy new tires and wheels for it and need the size for them.

How about looking at he tire spec label under the drivers door latch?

Hi so measure the rims diameter the rest should be the width and as we used to only have 70 series tires.Back in those days.

Most tire dealers have a reference manual.
It lists all the possible tires that are made for your vehicle.

Can't read the sidewalls because you rubbed the curb too often?
Pull a wheel, should have a easy to see sidewall on the other side.

Doesn't matter. What came on it is obsolete now.