Ok, I'm in the process of swapping an S5 T2 engine into my 73 240Z, and I need some help sorting out the ignition. The reason I posted in this forum is that I suspect you first-gen guys have more experience with converting carb'd cars to EFI, and some of the hassles that go along with that. Anyway, I'm going to run a Megasquirt EFI system, and haven't really found a satisfactory way to run the rotary's timing needs with that system. So, I was considering just using it as an "electronic carburetor" to control fuel, then running a locked distributor and a pair of MSD boxes to handle the spark. Any input?

 

You should try direct fire instead. Running an MSD through the cap isn't a very good idea (burns up the contacts quickly). Running an MSD on trailing is unnecessary.

If you MUST go with MSD, get yourself an S4 or S5 leading coil and hook an MSD box up to it. Run trailing like any stock 1st gen except move the wires over to the leading part of the cap. I'm sure others will agree.