Bench testing absolutely had to show that there was a problem with gov. springs. Especially when you missing a spring
Why would we even bother sending our pumps to bench test? Looks like you are better troubleshooter then those guys, so go get your money back.
Having your springs misadjusted or imbalanced could definitely mess with your idle and fuel delivery at any given RPM.
I'm not a pro, just using common sense.
Make sure you don't put your delivery valves up side down and set GSK nut at 0.040-0.050
1997 4x4 extended 132K, ATS Auto, ATS 5 star TC, 4GSK, 16* timing, 5x0.12s, #100, gauges, 6" lift, 37s, 4:10, Detroit locked front, Ford knuckles brakes and free spin hubs, rear LSD with Chevy wheel cylinders