My '69 (see it in the 3rd Gen. gallery) has 235 x15s in the front and 255 x 15s in the rear, and all fit perfectly. As far as air shocks, probably any replacement (ie. Monroe) will do fine.
PS. Welcome to ECC... are you stationed at George AFB? I went through your town last month on the way to Vegas for a tournament (Donner Summit required chains, so I took I-5 then east). How long have you been in?
HEy thanks for the response, I want the biggest tires that will fit without rubbing and stuff. I work at edwards AFB ,next gen war . I also want to know someone whohas bought a eng wireing harness and installed it .