I'm trying to fit fcr split singles to the stock manifolds right now and I found that the stock adapter's retaining ridge for the Mikuni carb made the Keihin sit off the central ridge by a couple of mm's. Thought about sanding out the Mikuni ridge to get spigot to seat all the way in but it's probably not ideal.Noticed that the manifold side of the stock adapter fit nicely on the Keihin spigot even though the spigot is 44.5mm's and the stock manifold is closer to 43mm's. Sudco said the manifold has a dellorto compatible grooves. Whats the OD of your malossi's? Found these (link below) and am thinking of trying them. In the mean time I got some radiator hose thats a good fit but you wind up with a gap as I dont think you want to butt the spigot and manifols together (although you could just worried about vibes and heat transfer). The stock ridge holding the carb off the seat creates a similar gap and just doesn't seem sturdy. The stock adapter, carb side is +- 46mm's I think, so it means clamping the heck out of it. Have you found any other sources? There's a guy on Ebay sells split singles, powerbarn, I think he has the malossi's and rubbers, don't know if he sells just boots, probably.