Holley Sniper on 700 hp big bock
Wiring is very important with a Sniper since you are feeding a low voltage microprocessor from a 12 volt automotive system. You really need to be super careful when installing the wiring for a Sniper. You also need a really good high pressure fuel system for a Sniper. Holley does make some drop in muscle car retrofit systems that include the pump, regulator and pre-filter inside the tank. I recommend using those whenever possible. Then you only need a high pressure filter and a single pressure line that feeds the Sniper from the tank.
Your engine must have a healthy cam to make 650 hp. In that case it is a good idea that you bought the Hyperspark distributor since you'll want to build an ignition curve with 20 or 25 degrees at idle and then 34 or 35 at WOT. Add 6 degrees of timing at low vacuum and smooth it all together.
Target AFR at idle will probably be around 13.5 to 13.8, WOT target should be 12.8, cruise target can be 14.5. Put those targets in and then smooth the table and you should be ready to go.