Picked this up before I decided to go full standalone with Link. If you aren't familiar they're popular with the Datsun crowd and makes the process of swapping a KA, SR20, CA, etc.. into any chassis pretty simple. Here's the offical shpiel:
"All Nissan EFI harnesses are for the most part, self contained. They usually only split into the chassis harness for power, switched power, a few different signals, and the warning lights. Nothing too difficult to understand and recreate.
This box incorporates all of the relays and fuses we deemed necesary and important. Over years of sorting other people's swaps, we have seen countless different ways to make the stock EFI function. You could twist a few wires together and jam them under the battery cable every time you wanted to drive your car and it would work but, it wouldn't be right!"
Here's an example of one of their diagrams for an S13 SR20DET:
Lots more info in this forum thread:
This is the guy who sells them:
Anywho, paid $175 for it and it's just been sitting in the original box for a few years. If anyone is interested it's yours for $125 shipped.
great info! i would copy and paste the post from ratsun here because sooner or later it may meet the same fate other forums have met