When I put the smallport in my AE86, I modded the smallport loom...
and what a farkin mission that was

Had to unravel it, identify
every single wire, extend all the wires that went to the main ECU plugs
and splice in a few extras to match up to the AE86 dashboard loom.
Scored a spare body loom plug and spliced that into the engine loom in
the same place at it sat on the AE86 loom... to make it all look factory
From memory, the only thing I took from the AE86 loom were the plugs
and wires for the wiper motor and screen washer.
Pic shows what it looked like during the trial fit... I've tidied it up since
then.
http://homepages.ihug.co.nz/~wjd/loom01.jpg
Took a lot of hours, spread over a lot of months to get it done... lucky I
didn't need the car as a daily driver. Everything works just as it should,
except when you bridge a couple of pins in the diagnostic plug the starter
kicks over

I explain that as the remote starter connection
Cheers... jondee86