Alternator charging Question

Thanks for the info 67DART. Without putting the alt back into the car, what is the best way to bench test it. I put my meter to continuity test setting I get the beep across both field spades then also each field spade to the alt body.
I can't remember what car I got it from but I guess it could have been converted to a single field. The guy I took it to is a very reputable rebuilder and a classic car buff, I am kinda surprised he didn't pic up on it LOL
He told me to bring the car over and swap it out and he would look at it..sounds like a bit of a waste of time when a rebuilder should know what the problem is to begin with!!!!!!or am I out to lunch on this? LOL
AL