got to pull the drum/hub and see if you can find the stamped number on the seal. If not, you have the hub in you hand just take it to the local auto parts store or camper parts place to match it up.
*Currently trailer-less but shopping
07' GMC Envoy w/ P2 controller (current TV)
88' Chevy K5 Blazer (soon-to-be TV)
74' VW Superbeetle (1303)