Alternator repair, a little show and tell.

Been a LOOOONG time. Make sure the rotor and stator are compatible, something that is difficult to do with rebuilts that may have been "mixed" parts

How did you test the rectifiers? You can NOT check them with an ohmeter/ multimeter. You MUST provide a substantial load for these. I'd guess about 10A or so. I used to have a small carbon pile used for testing generators. Same idea as a battery load tester, except easier to adjust. If not that, at least use a couple of stop/ tail lights jigged up in parallel to provide a few amps load

Examine the case halves carefully where the stator sits in the landing. These guys tend to "work" in there and then the the stator does not sit square. "Back in the day" I blew a few of these up from that---RPM and vibration. Then the stator rubs the rotor (you can see the marks) and this vibrates the windings until the stator insulation wears off as the windings wiggle around. With the engine running in the dark, you can see a "mini lightning storm" as the windings short against each other

Brushes may have become a problem. Last time I needed a set of brushes, from NAPA no less, they were just plain wrong. As I recall we ended up with 3 or 4 boxes, at least one, maybe two had different pieces than the other two. I basically pulled the parts I needed from two or three brush sets and sent the others back as defective/ packaged wrong.

Somewhere, some poor sap has the "really wrong" brush parts that were left over