I know my trucks stock tires were 7.75 x 15, and I have 225 x 15's on there now....but I'm not sure of rim size. I need some new steel wheels and have some spotted, but would like to avoid buying new tires. The other rims are listed as 8". Anybody know how to match those up?

I've seen 15x7's and 15x8's and both looked good on the trucks. If you are looking at after market rims make sure you get the right offset. If they are too far in they will hit the tie rods. I found this out the hard way when I had my 67.

also keep an eye on the hub bore, newer chevys use a smaller bore