Verify new wheel specs for my '83 please

We are planning on new wheels for the '83 (this is the black 'creek diver').
Can those in the know just reassure me I've done my homework correctly and these will fit OK:

Cragar S/S 15" x 8"
backspacing 4 1/4"
bolt circle 5/4.75"
lug nuts 7/16" RH

She'll be getting Firehawk Indy 500s - 275/60s on the rear and 225/70 up front (my tire man suggests this even though the tire specs recommend 7.5" rims as the widest for these tires)

Thanks

Roger on the main specs, but I certainly would stick with 7" wide wheels on the front if you're going to run 225/70s. The 8" wheels can result in debeading if you corner too fast or hit something, resulting in a potentially catastropic accident. The chances of this happening are low, but they're there. You will also find yourself wearing tires bad.

What would you think about 235/70s on the front on 8" rims?

It's a 28" diameter tire like the 275/60 (yes?) and specs call for an 8" wheel.
Also would still give him the 'wide tire' look on the rear versus the front that he wants. I like the idea of 8" all around as it keeps open the option of tire rotation should we decide in the future to go with 4 same tires all around. I don't want to compromise safety - this is for my son afterall!!

7" is still called for on a 235. Basically a 265 is on the upper end of the 7" width and the lower end of the 8" width.

Get a couple of 7" wheels to go with 4 8" wheels, keep the 7's with the 235s and use all 4 8's if you want to have the same tire size all around.

If your car doesn't have one, you'll want to install a rear antisway bar because those fat meats will have a lot of traction and will want to rotate the car a bit harder during cornering.

I had some 15x8's with 245/60's all around with 4" BS before on my 80. No problems at all and looked good. Although 265 or 275's out back would have looked a lot better.

I had some 15x8's with 245/60's all around with 4" BS before on my 80. No problems at all and looked good. Although 265 or 275's out back would have looked a lot better.
I'm running 15x7's with 255/60 Dayton S/R's all the way around. I also agree that wider tires are needed on the back to make it look right...