I swapped a 2.8L FI to a carb. 350, the alternator plug from the 2.8 is a 3 wire plug, I'm now using an older style alternator with a 2 wire plug, does anyone know the wiring conversion to go from 3 wire to 2 wire?.. any help appreciated..Thanks

 

Since you did the motor swap to carb 350, I'll assume nothing is computer controlled. I also assume you are using the older "cs" style alt which is self exciting.
I would not worry about that 3 wire plug at all. Basically you just need to run a power wire (8-10ga) from the battery to the power teminal on the alt (threaded terminal probably marked B+). You can then run another wire from that power terminal to the #2 spade terminal. You can run a wire from the #1 spade terminal to your gauge or just tap in somewhere under your dash.

Matt