Hi, to the best of my knowledge, all 73 and up Disk brake cars got BBP wheels. That means some 7-1/4 axles got BBP lugs. All drum brake cars had small pattern.
All the disk cars after '73 had BBP wheels. My '74 Duster has disks, a 7 1/4 rear, and BBP all the way around.
Congrats on the Feather Duster! If I weren't changing my '74 over to a Demon I'd be looking for those aluminum body parts. Pretty cool.
833 4 speed OD's aren't that expensive, I've paid anywhere from $100 to $250 for one, but no more than that even in good shape. Although most of mine are truck transmissions with the B/E long tail shaft. Pedals usually run around the $150 mark, give or take some depending on condition.
