Ignition boxes - worth it for the effieciencies

I have been waiting to try this on something. It will work with the stock Mopar electronic distributor. My only worry is spark jump on the smaller distributor cap. It will probably end up on my 354 Gen 1 Hemi. The wiring diagram has been posted a few times in several threads.

That is a Ford diagram.
The Mopar diagram has no 3rd wire ground from the distributor and the ECU is grounded via it's mounting surface, or with a dedicated ground to the ECU. (can be done either way)

CudaJames, you can get one of our pre assembled HEI kits using the newer moisture proof ECU and connectors here if you are considering HEI. www.classichei.com
Our kits are pretty popular, and everyone is really happy with the performance of them.
$149 shipped to the lower 48, and they come with everything needed to be running HEI right out of the box.
(E core coil, 8 pin module, moisture proof connectors and all needed wiring pre assembled)