Kinda new to this site I have a ? Rims that cross refernce to this truck? My tire guy says my rims are to thin That I need 10" rims. The tires are 33x12.5 R15lt .This is my truck a 1990 with arb bumper and OMU springs.Martin
Generally rims are no more than 4" narrower than the tire width. Those stock rims are only 6". An 8 inch rim would work fine with those tires. Stock backset is 3.5 in. if you didn't know and the bolt pattern is a 6 lug on 5.5" centers. Matches the old chevy six lug but uses a different backset. You can use rims with a different backset but you may need spacers.
There are a lot of options, so search around the site and you will find them