If you're putting the Weber carb on a 261, you really need a pair of them. Biggest problem is the one bbl fitting, it's not big enough to allow proper flow. My friend's 261 which is in the 200-225 hp. range has the dual Webers, we're thinking about cutting the one bbl fittings off his manifold and welding on 2 bbl fittings, but that's one of those "someday" projects.
