/6 to 360 swap

Well, I'd upgrade many things, not just the suspension.

-I'd use a small block 904 trans, you probably "should" upgrade to an 8 3/4 rear or at least an 8 1/4. You may need a longer or shorter driveshaft.

-Upgrade to later model large bolt pattern disc brakes if not already equipped. Upgrade the cooling system for a V8. I would use 1.0" or larger, but not by much, torsion bars, as these cars are already under sprung from the factory.

-I'm assuming you have the proper conversion mounts?