I'm looking to get the extera preformance possible from the relatively easy and inexpensive mods I read about here and I just don't get a few things. Needles- I understand the concept but don't understand the differences in the brands and benefits associated with each. Same goes for the shims on the needles. I also noticed when I was playing around on the new jetting calc that this adjustment would also effect you jet size. Does this also improve your mileage?
