I have an 85 Camaro TPI 305. I think the alternator is crapping out cause the voltage will dip unless I'm on the gas. The battery has died on me a couple times, so I took it to Kragen, they ran the test and said the alternator is charging erratically and should be replaced. But they come up with like 4 different options of alternators, (varied by amperage mostly) and he couldn't recommend which one. so I need help figuring out the correct one. Any advice?

 

Good Luck ! I JUST WENT THRU THE SAME ISSUE WITH MY 87Z- TURNS OUT MY ALTERNATOR WAS FACTORY INSTALLED ON A 1988 CAPRICE 4.3V6 WITH POLICE OPTION 140 AMP - MINE HAS A 4 GROOVE SERPENTINE PULLEY , BUT WITH AN OLD STYLE LARGE CASE AND NEW STYLE 4 PIN CONNECTOR - IT SEEMS TO FIT LIKE A FACTORY PART ON MY 305 T.P.I - WHEN WE TRIED LOOKED UP MY PART BY APPLICATION FOR AN 1987 Z- 305 T.P.I ,ALL OF THE ALTERNATORS WERE WRONG -THEY WERE THE NEWER STYLE /COMPACT TYPE AND WOULD NOT FIT - TRY TO FIND THE ORIGINAL STAMPED PART# ON YOUR ALTERNATORS CASE - THIS WILL MAKE SURE YOU GET AN EXACT FIT - ANY G.M. DEALER CAN USE THAT PART # TO TELL YOU WHAT AMP YOU HAVE - ALSO THA AMPERAGE IS SOMETIMES CAST NEAR THE PART#