best type alternator?

I have several early A cars i'm piecing back together. I was "shopin" alternators at couple of local independent auto parts stores. I ordered an alternator at each store. price is $25-30 less than the "chain store" plus the owners warranties it for life, period. I ordered the round back a one store and a square back at other but asked for single ground field units. I got the same square back ( rated 60 amp) alternator at both stores, the "second" field connection on both sat on top of the insulator, each had slightly looking brass connector, neither would take a wire though.
I guess I can hook it up and see if car starts, runs???