M10 to M42 swap quick questions

[irish44j]

I'm about to pick up a complete/running M42 with tranny, driveshaft, ECU, full wiring harness, and (I'm assuming) various other parts with it (since the owner is doing a turbo M20 swap, I'll assume I'll get all M42 parts that don't swap over).

This will be a swap over next winter, so I plan to do an engine teardown (to some extent) and accrue any other parts I need (radiator, header, etc)

A couple quick questions:

1. For the wiring, will I be able to use the main wiring bus from the M10 inside the firewall, or will I need to re-wire everything under the dash with the new harness? e.g will the M42 ECU use the same plug as the Jetronic, gauge cluster, etc?

2. ok, just that one question actually. But any other comments are welcome concerning things that I should look out for or think about.

[Link]

Also interested.

[SoopaGhetto]

1. For the wiring, will I be able to use the main wiring bus from the M10 inside the firewall, or will I need to re-wire everything under the dash with the new harness? e.g will the M42 ECU use the same plug as the Jetronic, gauge cluster, etc?

i know the c101 plug is different between the two. you shouldnt have to rewire everything just get a wiring diagram and figure out if you want to cut the m42 harness and adapt it to the square plug or make an adapter from square to round. i could be wrong but i believe this issue is there for other swaps too

[chance]

I'm pretty sure the Ecu plugs are different