When I had the stock ignition system in my Vortec 350 I ran an AC Delco platinum that was gapped at 0.035" per a GM TSB. When I swapped to the Davis Unified Ignition setup I ran NGK 7164s gapped at...

The flash based LT1 PCMs do, the older chip based LT1 ECMs do not.

PCM controls the Dwell on a Vortec atleast. Guessing it is the same on a LT1 since I believe atleast the OBD2 LT1s used the same module.

The overlap is really a non-issue with these PCMs. I have run the same values on 4 different cams. The factory Vortec 5.7 Express van tune offers a great starting point for most LT1 setups.

FWIW...

Biggest issue I have seen and this was fixing what a "PRO" screwed up was getting the injectors & coils in the right order at the PCM and then correcting the injector bank assignment and firing order...

My 0411/24x/CNP/DBW swap did not take too much tuning honestly speaking. Swapped in a 2002 8.1 engine operating system, copy pasted most of my 350's old table values into the tune. Flashed the...

I will also not get into the fact this engine also gained 27 hp and 6 ft/lbs from a valve spring and retainer change. Lets just say I had a local machine shop pickup and install 2.02/1.60s in these...

0411 runs better and the Blue/Green 1 meg runs even better and there was a 16 rwhp power gain at redline in my Vortec 5.7 going to the Coil Near Plug setup. I am currently running a Flex Fuel sensor...

EFI connection 24x swap with an 0411 is how I would fix the optispark in a LT1. The only non factory part at that point would be the reluctor ring itself.