FYI: The replacement bearings they sell on many sites including classicparts.com are seemingly the wrong size or else built to a sloppy spec. I'm in the rear axle on my '66 burb to replace axle seals and thought new bearings would be a good idea. That was a mistake, the old ones had about .004" of radial play, but the new ones had .008" !!
Lesson learned: Keep the old bearings, or else find some new old stock. New SKFs from Thailand cant beat a 60 year old Hyatt from USA.
A couple of other things I'll mention is that the axle shafts in the 12 bolt rear ends are known for wearing and that plus the looser tolerance in the bearings will add up to more radial play. I realize everyone would prefer something like .001, but I don't believe you can get that without also replacing axles and I don't think .008" is enough to worry about...that being the thickness of two sheets of common copy paper. You'll also have expansion with heat from operation, so usually it all balances. If you were using your Suburban to travel the USA all the time I might be inclined to get new axle shafts but if you're just driving around NM, I think you'll be okay. Once upon a time there were bearings that were made so that they'd run on a different part of the axle (can't recall what they were called) but friends said they thought they were more sizzle than steak.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Jon G - I think your looking for "Axle Saver" bearings. Evidently they can still be found for Chevy 10 and 12 Bolt rear axles, but not sure if these will also work with truck axles???
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)