97-04 GM Truck / SUV Mount. Tahoe, Blazer, Suburban, Yukon, Silverado, etc.
This is the most common unit used for brackets as well for multiple alternator systems. 4.3L, 4.8L, 5.3L, 6.0L, 6.2L
This is the externally regulated option for guys running LTO, Cmax, and Proto Style battery banks and want a higher charging voltage.
Several Color options available as well starting at 25$.
390a units for GM vehicles have around 190a at idle, and 400+a of peak output potential around 1800-1900 engine rpm.
These units also fit older 91-96 applications with a AD244 swap, you can find information on how to accomplish this swap on youtube, and google.