Where to buy correct alternator for a 1969 340 swinger non a/c car

i don’t really care if it’s numbers correct , i just don’t want to burn up my wire harness or my voltage regulator. From what i’ve read on the forums the 60amp that’s available is pushing my luck on the stock harness. i’ve also read that some of the rebuilt alternators put out too high of voltage to the stock 69 and older regulators.
It’s a little confusing on figuring out how to identify the correct alternator. I kinda get the idea that finding an unmolested original is pretty rare nowadays.