Father-Son 1974 Duster Project

They are 7", 4-1/2" backset. I have another thread going to try and cure my ignorance on the topic, lol.

Nubs on Cop Wheels

The appeal of the cop wheels is they are cheap, they are strong, and you can wrap a lot of rubber on them.
I'd say go for it on the cop wheels. Don't know if I would get hung up on the 'nubs', I think I would paint them and run em. If you want to upgrade later they would probably be harder to unload if modified.