difference between DUB and rims?

Dub is a brand name . A lot of wheels are called Dub because of size and style. Dub wheels should be marked with the brand name, other Dub style wheels are more or less knock-offs. Not the real deal but they look pretty much the same. Ask the sales guy if they are real " Dubs" or copies made by someone else then find a place that has the wheel you like and what size you can go to. A good tire shop should be able to tell you. they should check height, width, backspacing, and clearances. Sounds like he'd be better off keeping the wire wheels. You sure they're 6 lug. I think you could get something in an 18" - 20" that should fit whether or not they're brand name Dub or something else, American, Crager, Micky Thompson, etc. Hope this helps.

dub is a generic term. it used to mean 20. it is now used to reference wheels in general