Can't speak for the Sniper but for Fitech, you can run with just the regular distributor and later let the Fitech control timing. One less item to not be concerned with until your ready or leave as is. I would imagine the Sniper has the same ability.
you can use your stock stuff. The sniper comes with a coil driver, that again will need a good power source on the pink wire will in crank and run positions. over 10 volts if possible. also the Sniper is very sensitive to RF noise so pay particular attention to which way you have the wiring ran.
I am also looking into the Sniper system and contacted EFI System Pro and they were very helpful and also found out that there is an in-tank fuel pump and sender combo available for the gen 1 nova eliminating a fuel return line.
Well, I'm looking at the Sniper also. Instructions are pretty clear on having a designated 12V source with key in "on" position and start. From what I have read when key is turned on, fuel will be provided for the start process. So be mindful that you don't turn key off and on checking something else in the car and not starting engine. You could be flooding engine. Also separate power and ground needed and recommendation is straight to battery. Regarding fuel supply, Holley has a in tank supply that is supposed to replace the fuel supply/fuel indication is stock tank. Link below.
• This in-tank fuel pump module is a high-pressure unit that flows 255 liters per hour (LPH) and is capable of supporting electronic fuel injection (EFI) engines producing up to 550 horsepower • Fuel pressure is internally regulated to 58 psi eliminating the addedexpense and effort of...
I installed the Sniper on a 66 Chevelle. You can install it without making any changes to your existing ignitions system. The coil driver can be used if you decide to step up to Sniper controlled timing, in place of an ignition box. It just doesn't provide quiet the spark power as say an MSD 6. If your ignition is working good as is, stick with it while you work out any bugs with the fuel injection. It's easier to troubleshoot if you're only doing one system at a time. You can always upgrade later.
We started with an hei, then upgraded to the Sniper distributor and a DUI coil, with the coil driver. We still have the option to upgrade to a multi-spark box later if we choose. As for now, the adjustability of the timing is awesome. I had my son run the laptop as we made runs on the road and made adjustments as the seat dyno indicated, without ever raising the hood.