Mercruiser 350 Aternator wiring help

Good evening all,

I have just completed a new motor (Chevy 350/4 bolt main) upgrade in my completely rebuilt 1997 Formula Falcon 2000 BR. I upgraded the belt system to a 6 grove single belt (serpentine) system off of a 1990 Chevy truck. The alternator which came with the system is a 4 wire "pig tail" type. As the system is off of a 90's model Chevy truck, I believe the alternator cross references over to ADR0315 (7SI marine application IR/IF) or Delco 1902066, 617. My boats wiring harness has the standard Orange, Red, Purple and Black. The alternators pig tail contains is 3 wires, Red, Brown and Black with PLFS stamped on each section. Can anyone please let me know which wire tie in where and please provide a diagram.