Need to mount a larger tire on the rear of my Riviera for ET street radials, the stock 6" rim will not allow that.
I wouldn’t mind a picture if you have one, but they’ve been proven to fit over the drums? Did they come off your own Riv?
https://www.wheelvintiques.com/o-e-chevy-ford-bare-finish.html Its a basic steel wheel, not sure why it wouldn't fit over the drum. I have the same wheel in the basement. I can take measurements for you
Most 73 - 87 Silverado pickup rims were either seven inches wide (seventies) or six and a half (eighties). Perhaps they had a wider one that was not a six lugger.