Im pricing out the parts for my nitrous setup, how do I figure out what size braided line I should get? -3 AN.. -4 AN.. -6 AN.. It's a small setup, so im assuming I can save money by getting the smaller, -3 AN diameter line? The sizes that the -4 AN sized line comes in are more accomodating for my setup plans however. My bottle will have a -4 AN output.. so now that I think of it, I should go with -4.. i think..