New Alternator To Avoid

I have had two rock auto alternators not work at all out of the box. They also will send you a single field alternator in a square back case which wouldn't give full range of adjustment on a poly motor I had. Points ignition. They do not tell you, they just send the square back.
I have one of those rockauto squarebacks. Single field. Have not tested it yet. I guess I probably ought to.