Jeff the wheels are available but you have to give your Z28 vin number to buy them from GM at this point. Wouldn't be too hard to get though, there's a couple of sets for sale on Camaro5 forum already.
I just got a set of them and mounted some Michelin's for a street set for my Z. I had that same thought to see if I could bolt them on my 70 Camaro. I will measure the backspace on the front wheels today but the other day I did a quick measure and thought they were in the 6 1/2" range. The center hole in the back of the wheel is too small to fit the hub on my DSE spindles too, and I hadn't even checked the bolt circle
