94-96 Impala SS wheels look pretty good on those trucks if they are lowered a little bit, but a cheaper alternative is the 80's truck 15X8 rally wheels.
any GM fullsize car with the HD suspension has the bolt pattern and hub diameter you need- something like an Impala or Caprice wagon built from the early 70's to the 90's. fullsize Ford cars of the 70's also have the 5X5 pattern, too.
one quick question about the 67-72 trucks, if anyone knows- what was the difference between the 1/2 ton 2wd truck that had the 5 lug pattern and the 1/2 ton 2wd trucks with the 6 lug pattern? in the early 90's, my grandpa gave me his trusty well used '70 1/2 ton 2wd long box truck and it had 6 lug wheels on it. was that because it had the "truck arm" coil spring rear suspension instead of leaf springs?