Goofy, I think the only way to get a single carb manifold is to fab it ourselves. When I was having my float adjust problems a couple of weeks ago, I was seriously considering this. When I had my carbs out, one of the 7 times that week, I took measurements and recorded angles of intakes. Drew up a few ideas. Seems the best would be like a extended plenum design. This would lower the velocity for most of the distance so it would lower the chance of icing in low temps. Thinking about a 38mm mikuni pumper jetted one size less than the 883 set-up. But I have worked out my carb problems so this is on the back burner.