Neat bus. Surprised it has a 392 in it, not original then? The 6BT would be a good choice, will need to cut the firewall and make a doghouse. That is not a big deal though. Interesting rims, they do not look like split rims, have they been modified? or are they split in the middle rather then a lock ring on the side? The ones that are split in the middle are a real pain to work with. I would not keep that type except for a restoration.