I have heard a few times that guages similar to my Autometer a/f guage is best suited for a light show but how accurate are these things. I bought it because I was told by a few they are essential in a good nitrous kit.
The questions Should my a/f ratio always be constant? Is it better to be rich or lean. I'm guessing rich? What is the factory a/f ratio? When using nitrous, what a/f settings should be altered for 50-150 shot. How about 150-250? Thanks for clearing this up anyone.

Only wideband O2 sensors are accurate at points other than 14.7:1, so yes, your current a/f guage is pretty useless. The A/F ratio should be constant, but only at comparable operating conditions. For example, you can't compare idle A/F vs. WOT A/F. Factory mixtures usually come in around 11.5-12:1 at WOT, a touch on the rich side, but fine for nitrous usage. The A/F ratio shouldn't be altered no matter how much nitrous you run. You'll always want to shoot for that 11.5-12:1 when you're on the bottle. For more naturally aspirated power, you'll wanna see 12.8-13:1.

Thanks man, thats what I wanted to know.