Edit: My question was running dual rear wheels on a single rear axle by using extended studs. After more research it has become clear that the inner wheels will hit the leaf springs as the srw axle is narrow. Hence the need for dually wheel spacers.
I have zero interest in running adapters, not worth the risk.
I'll be looking for a dually axle or just runn single wheels.
I would erase my post but it still may be useful even though I answered my own question. But mods feel free to delete of you see fit.