How good is a 2speed powerglide auto trans?
yes,just dont put a big strain on it.
By strain you mean... large loads in bed & taking off fast?
pulling heavy loads,takeing off fast is ok,do the burn outs.
When new, those transmissions were a piece of crap, but that's what was offered at the time. If you want to keep it original, keep it, and have it reworked. I'd go after market like Tremac or something that will give you power for loads and good mileage for road driving and reliability. the bands wore out constantly when used or slightly abused on the 2 speed slush box.