ok so heres my issue. Doing a jdm type r swap into my 99 Integra
I baught a 99spec (Stamped) JDM B18C Type R. It came with a 4 Prong alternator plug.

But im using a 1999 Integra LS engine harness. Which has a oval 3 Prong alternator plug in.

I will be using the JDM Type r ECU.

So heres what im thinking. Since i am using the jdm ecu, it will be reading 4 wires. If i buy a 3 pin alternator to fit my 99 LS harness, it wouldnt run properly.

Has anyone ever ran into this problem or know a solution to this?
Also thinking of cutting and wireing the 4 prong plug from the jdm harness i have and putting it on my 99 LS harness than running the last wire to the ecu. But do all 4 wires go to the ecu and what pins would they be?
Also what does each wire do that would help me.