with a 70cc bore kit what size carb could i run, im ordering the airsal 70cc kit with a techno estroil exhaust custom intake manifold to match what ever carb i get but i don't know what is to big. i was thinkin the phgb 21mm race carb but i think thats a little extreme. keep inmind i am looking for the best possible performance, so what would be the best the 18, 19,20, or 21 mm carb? i also ordered an msd coil with 8.5mm wire and rewired the whole harness with 16 gauge wire to withstand the new coil.