'71 Duster 340 Battery getting overcharged

Hi,

The alternator in your picture is a "round back", not a "square back". A 71 should have a round back alternator with an isolated field or two field wire connections. If you only have one field connection they gave you the wrong alternator, one that is for 69 or earlier. The round back type with two field connections was for two years only 70 and 71. The square back came in in 72. You can use it on your 71. The green wire goes to one field connection the blue wire goes to the other.

As to your "autozone expert" if he knew anything he wouldn't be working at Autozone for minimum wage. I would take the one you have back and insist on the right one. Better yet get your money back and find a real auto parts store.

The alternator you want will have two field connections with insulated brush holders.