the wiring would be easy enough, but thats assuming he has all the stuff for the auto. control unit and looms etc
as the exa auto is a very different gearbox to the silvia one so i'd doubt that if it is an electronic one that all the control stuff is the same

auto control unit only has 5 wires going to it from the main loom
Assume all the rest go to the auto or the dash

tacho signal
earth
ecu pin 56, A/t Control Unit
ECU pin 57, idle switch, tps switch, full throttle switch
ECU pin 48, TPS power output

I have studied up and know where the wires (should) go now.

It's just a matter of getting the plugs to suit the AT (2) ECU

I don't fancy hard soldering up into the plug slot of the ECU or pulling it apart.

I will provide a full update once i beat it

I got the exact plugs i needed.

Just for anyone else dumb enough to put a Silvia Auto into the 1200 behind a CA18 here's some advice.....

you can get the plugs for the AT computer from a VL commodore or from a Pintara. They will be used on the Main Engine ECCS, but you will need to get an EXTRA plug because the pins will not be in the right slots (i.e. there are pins missing in the plugs and you need to either move them around or insert more in the vacant slots for the Silvia AT computer).

I advise getting the extra plug because no-one can tell me where to buy new pins