Round Back Alternator Rebuilder

Strangely, the square-back alternators in my 1982 Dodge Aries 2.5L would fail the diodes regularly. Only the 3 diodes on the rail hanging in the air (positive?), visible thru the openings. The other 3 diodes on the rail which clamped to the housing (negative?) never failed. Eventually, I would buy just the diode set from an auto electric supplier, and got good at splitting the alternator case and installing them, working underneath the AC compressor so I didn't have to unbolt the AC compressor. Figuring overheating was the culprit, I started cutting cooling fins in the rail, which seemed to last 2 years instead of the normal 1 year. The guy at the shop said those diodes regularly failed. I suspect the transverse engine mounting was the cause, since one never heard of them failing in RWD cars of the same time. The Aires still had a carburetor with mechanical fuel pump, but did have an electric radiator fan, so perhaps that load was a reason.