RE: MY New VA MKII RC!! :)
Well, I checked my engine and the crankcase has a thread on the outside to hold the ventur insert in place using a ring clamp that is the outer part of the venturi. I guess this is what AJ reffered to when he said I'd have to tap the existing hole. If so I'll tap it with the proper metric thread. It sure sounds like that size is a 6mm x 1 mm metric thread. If so then I've got a good supply of those.
Larry, I'll contact you through your site or by PM about getting one of the old carbs that I can modify. It'll be easier than trying to source a needle valve and spray bar for a custom carb.