Make sure the bolt-hole size is right, too.  .

As I understand it a Chevy pattern to fit a mid nineteen seventies half
ton truck will fit. There is both the issue of bolt pattern and fitting
the Studebaker brake drum. The Chevy Wheels fit both. I moved from the
original wheels to Chev wheels a couple of years ago. I got seven inch
wide wheels and found it a tight fit to prevent binding on cornering so
eight might not work well at all. The tires were also larger than the
stock originals so the speedometer reading is about five miles per hour
off at sixty miles per hour.

Hope this is of some help to you

Colin

Wheels can be tricky.  Make sure that they are steel so that they clear
the "hump" on the Stude drums. A "flat" wheel will not fit.

Also, 8" may be a bit big for the front.  Watch for tie rod etc.
interference.

And, expect your fuel economy to drop precipitously with bigger
wheels/tires.  Don't ask me how I know! (After putting on Lincoln wheels
and 235 tires)

Then, there is that nagging geometry issue...

JT