you can get 6 inch wide wheels from 73-79 trucks. i don't know what size the 80 and up trucks are. but they probably wont be 7 1/2 unless you get some of the lightning wheels or the bullet hole wheels. the bullet hole wheels (modulars) are 8 inches wide.
just keep searching craigslist. after a year i finally found the 8" wide wheels i was looking for. i also know that doug comer on this site has some 8" wide factory wheels for sale. or at least he did.
wanting to buy a mercury tailgate! "the man who is swimming against the stream knows the strength of it".- woodrow wilson