You could save a lot of money going with a 32mm Mikuni instead of The RevFlow, if you want a single carb. If using dual Mikunis, like a lot of us, don't go any larger than 26mm or you will compromise airflow velocity. If interested in the RevFlow, be sure to read up on it. There have been issues that RevMaster has supposedly corrected. I think a lot of the Sonnex owners are using the RevFlow on larger than stock, 4-cylinder VW's.