I have a 30mm Mikuni carb for sale. Came stock on a 1987 Polaris Trail Boss 250. I don't see why you couldn't use it on a Blaster. If interested, PM me or call/text (814)706-3930.
Free bump! I bought a 3mil stroker Blaster with this Polaris carb on it last year. The carb worked great. I seem to recall the stock intake boot was still used. I know this carb takes a different pilot jet, but I believe it uses the same style main as our Blaster's stock carb. Just fyi.