Early A-Body "Over-Engineering"?

those are bog standard off the shelf cage nuts by the look of it. they are used on server racks fairly often these days. they allow for a bit of weeble wobble if parts are not perfectly to spec and make repair easier by having the nut still replaceable, but you dont need to hold it or get a wrench to it when tightening or loosening.

as for cables, stainless cables are fairly new. plain steel will get moisture inside, rust and stick. even stainless can freeze up in the winter. not much more excitement to be had than a stuck open throttle in winter driving conditions with no ABS or traction control and old bias plys