The Holley Sniper might have it's issues since it is much newer. I wouldn't say that FiTech created a lower quality product either. The unit I installed has been running +30kms daily for the last 90 days right through a Northern Ontario winter. Grounding with EFI systems or any automotive electronic system is very important. Ground loops and marginal grounds have no effect when you are talking about light bulbs but when you have PWM(pulse width modulated) signals driving fuel pumps and processors requiring good quality supplied power, that ground becomes important. Bad grounds can create all kinds of electrical noise issues. That fuel pump negative lead should be run back to the TBI mount bolt. Don't scratch away 45 year old under-coating from the rear frame rail and stick it there. Make quality soldered connections on all joined wires. I even solder the crimp ring connectors rather than relying just the crimp. Old Mopars are terrible for the factory bulkhead connectors, a poor connection through that cause issues depending on where you steal a key-on signal from. My suggestion to anyone who is troubled with units cutting out or erratic operation / freezing up etc. to review their install and bring all grounds back to one single common point and inspect all connections. It's not convenient to put your 2 AWG battery negative on your TBI stud but use a good heavy braided ground strap from the TBI to that single ground point on the block with clean polished metal with star lock-washers and dielectric grease.
Also, pay attention to where your wiring runs. Stay away from ignition wires and use resistor ignition wires.
I'm just tiring to help fellow members with a reliable trouble free installation for any system they consider.