Hi Folks,
One update coming up. ;-) A big factor in choosing this distributor was the ability to create and store multiple tunes in my phone. My 400 is .030 over and with the pistons the PO used, real world static compression is around 9:1. That said, even with the 068 cam, it was pinging like a bell choir, and I couldn't get the Q'Jet to run right. Believing the preignition mischief was was ignition-based, I pulled the trigger on this unit. It turns our the Q' jet was the culprit. A rebuilt Q'Jet was junk and a waste of money - same issues.
So, I picked up a Holley Sniper Quadrajet EFI. The installation is worthy of a whole separate thread, but now that it's done and with the fueling issues handled, I'm happy to report that tuning the ignition is really waking up my GTO. More importantly, I'm zeroing in on getting the thing to run reliably and ping-free on mid-grade (89 octane around NE Pennsylvania). Doing the tuning from my smartphone is a breeze and the new version of the app has a nice real-time gauge set feature too.
So, after all this time, I think I'm finally getting the results that I was looking for when I bought the distributor and would buy it again again. Oh and yes it really did need full 12v. to run right too. Because of the addition of EFI, a vacuum pump and future considerations, I did install a small aux circuit panel in the engine bay. Activated via a relay, this panel provides 6 additional fused ignition-on 12v battery power circuits for whatever else I need. No trouble so far.
FYI: Here is the link to my installation I posted over in the Street section:
https://forums.maxperformanceinc.com...36#post6159336