I run 37/39 nozzles 50cc pumps, blue cams primary #2, secondary #1 hole on my stock stroke 340. This tune gives me the best 60' time with progressive linkage and .020 t-slot, 6 psi fuel pressure, 1/2 site glass up front, slightly above 1/2 secondary bowl. I also make it a habit of purging any air prior to the first pass of the day.