I have a 98 suburban c1500 which was equipt with the 105amp alt. I've been wanting to upgrade it to the 124amp. Seems like the time may have came. I was gonna order a 124amp ac delco. I see there's a rectangle plug instead of the oval one. So I'll also order a new harness. Does anybody know if I missing anything? also i see its 4 wires on the harness and i could of sworn the stock harness has 1 wire. Does anybody know how to address this?. Any help or tips will be appreciated. I know there's a power supply from the battery. That's not what I'm talking about btw.