This is what I did tonight. This is the remains of the camry V6 ecu with all the pins removed that megasquirt will not use in the stock 3sgte loom.
Looking pretty sparse in there.
Now this is just an attempt, I am not 100% happy with it but short of cutting the plugs off the stock harness and wiring it wire to wire I am not sure what to do. I would have liked to see how others did it but I don't know of anyone who has done it this particular way although I don't doubt there are.
Here is a close up. The wires were wrapped around the pins, thoroughly soldered and then heatshrinked. The three extra wires are the EDIS ignition wires I will run seperate shielded wires for (except pin 24 as this already has shielding as part of the diyautotune loom) and the IAT since obviously this will not be in the AFM anymore.
The gray coiled up wire is going to be a TVIS wire from the stock loom side for when I work out how to operate it using megasquirt in the future.