Aftermarket wheels, 17" (maybe 18) BBP

I understand that. I am ok with spaces that slide over the wheel studs, but not bolt on ones that have their own wheel studs. To each there own, but I don't want to run them.

That's why I went to an F-Body 8.25. It allowed me to use cheap Mustang wheels without spacers, and the cost was significantly less than an 8.75.

Not really an option, I'm keeping the 8.25" I have.

If they are similar to the cop car 15x7, offset is like +1/4". With a 235 series tire, that would have about 4.875" from the mounting surface to the back of the tire. What size rear tire right now?

215/65R15.

How much room between the tire and spring at the front of the tire?

Any idea what size tire you would like to run?

Probably a 235 or 245/50R17.