S14 into 320iA?

[Mr. Horsepower]

Playing with the thought of doing this swap into my facelift 320iA 1990.

I wonder if the diveshaft from the E30M3 will fit the 320iA diff?
Is there any tricks with cables that I need to know about except from the starter interrupt device for the automatic transmission?

Thanks

[FredK]

The driveshaft will fit. Depending on the production date of the driveshaft, it may have an early or late style center bearing support. You may have to swap it to the late center bearing support.

Preferably you should source an engine wiring harness from a late model E30 M3 with a three pole starter. That way the electrical system during start is "unloaded" in an identical fashion.

+12V is also supplied through the round connector at pin 20 at the fusebox (C101) for certain late model cars. Ensure the wiring is the exact same on both sides of the round connector. If the chassis side is a ground, then the wires could burn up.

[Mr. Horsepower]

My M3 is 1987 and the engine that is mounted in the car is 1990, same year as the 320iA.
Thanks for a good answer by the way!

The round connector you are talking about is the one sitting under the plastic trim on the firewall right? Next to the brake booster.

[FredK]

Yes, that is the exact connector I'm talking about. It is a 20 pin connector.