I bought Compucar's Nitrous in a Bag system. It comes with five jets the smallest being .039. I plan on inserting the steel spray line supplied with the kit in the rubber end cap of the air filter along the axis of the filter spraying straight down the bore. They suggested going one colder plug and gapping at .035. I am running NGK TR6's gapped at .04. Should I follow their directions? Also, can spark plug gap alter the A/F ratio and if so, what direction results in a richer ratio? I plan on spraying a very small shot for cooling purposes and probably won't go over 40. I will do the testing while on a dyno and may make a .031 jet here at work for the first size to start. What size jet would be a good size to start with?