When we ran a full service chassis fab/turn-key hot rod shop a number of years ago, it was always useful to have threaded things around to weld into the frame for some kind of mount, etc.
Here’s a list of all our threaded things for your reference:
Alternator Mounts
Small block Chev alternator mount kits in bare steel, available welded and ready-to-weld. Pieces are also available separately. Kits include all hardware.