I've been using the VM38's for years, been very happy with them. The 330 main is about right, I've used 20, 25, and 30 idle jets, depending. Usually, the carbs I find at swap meets have been set up originally for sporty's or big twins and have worked well with the slides and needles they came with. Usually the are originally from Sudco, who do the original setup. I've played with slide cutaway, but found the original ones work best. Don't remember the number just now, but can check if you like. With the right pilot for your machine, they are first or second kick machines, with out bothering with all that primer kick nonsense that Linkerts seem to require. Yes, "the opinions are mine, and your results may vary"