My experience when I posted before was with alky. Probably should have put that in their. Anyway I'm pretty sure 7-2 to 6-2 is the metering rod that should be used for the Zilla. First number is top end. Larger is richer. Second number is midrange, again bigger the number the richer it is. So a 7-2 is richer then a 5-2. I ran a billet bowl and a 3.5 float needle on a pump with a PE1 or PE7 needle which around a 19-2 (for alky)