One of the problems I had in making the conversion was the neutral safety switch. Here are the different types.
I had several choices about how to solve the problem, but decided to just build a pigtail to go from the existing connector in the car to the connector on the 300D transmission. Here's the finished pigtail.
What I did was get a NSS from a 300D at the junk yard and cut it in half - I only needed to use the male connector.
Then I soldered the wires from the connector of the 300D NSS to the switch leads shown below on the half of the NSS I got at the junk yard.
Then I put the two halves together in a vice and filled the pigtail with urethane. Might have been better to use epoxy, but I didn't have any at the moment.
The reason to go through all this trouble was anticipating that at some point in the future if I ever need to swap out the transmission with a different model, I can just unplug the pigtail and plug in the standard connector.
By the way, just for the record, the two connectors closest to the square key, are the starter circuit and the two connectors furthest away from the key are the backup circuit. It's just a switch to complete a circuit, so it doesn't make any difference which wire goes to which connector in the pair.