Powermaster GM 12si style alternators feature excellent output at idle. 12si are one unit for 1 or 3 wire hookup. They fit most GM brackets from 1964-1989 and are a popular high output upgrade for 10DN & 10si alternators.
Powermaster 37294-360
GM 12si Original Look
1V pulley
Baffle & cone
1-wire or 3-wire
100A at idle, 150A top end
Brushed finish
If using as OE 3-wire plug-in, you must have a dash light or resistor in line to avoid damage to the regulator