I too run a Sniper and have for several years. The biggest issues I have had are with starting. Not that it didn't start, it just seems to be too advanced or inconsistent during starting regardless of the cranking degrees value that I set. When I run EFI full only and an unlocked rotor calibrated with full advance at 3000 and 23 degrees of advance to give 32 degrees of total advance it starts with a flick of the key cold or hot. No more hard starting due to heavy advance. Magnetic MSD distro with MSD 6AL. Maybe a Hyperspark would eliminate this?
Also power is dropped on the ignition circuit between start and run on my Dart. This reboots the EFI and I see this on the display. A time off delay relay takes care of this issue. I have added relays to the ignition and headlight circuits to reduce the current and voltage drop through the bulkhead connectors.
