I have been running dual carbs and three carbs for a long time, and as stated, they require work, and a ton of tuning. It is not a bolt on and go operation. My 250 does run better with dual W-1's from a '48 Chevrolet, #574's, but I also have a $200 air fuel ratio ( wideband ) gauge and vacuum gauge to help tune them. I built the dual manifold I am running, and have it mounted to a stock exhaust manifold. I did this for the heat, headers do not provide the needed heat to vaporize the fuel.
You probably know already, but aftermarket replacement carburetors are mostly pieces from hundreds of carbs and very few are jetted or configured correctly. If you truly want dual carbs, by cores and rebuild them yourself. Both MUST be identical in every way, right down to the minute adjustments.
Joe
