Miker. From earlier posts I reckon this is the 1951 Plunger bike. Space is tight to the top frame tube, a later 376 Monobloc carb will just about fit, but without any filter. My bike came like this.
You've got the correct earlier 276 Type (remote float chamber) and if using an original airbox, get the correct rubber connector. A7 type has smaller carb connection, height of the outlet is lower as well to compensate for lower block height. With the right bits it all fits in with a squeeze. Folks use cables with in line adjusters to avoid sharp bends under the frame tube, rather than the usual adjusters above the carb.
A plain screw on spigot in place of the bellmouth jogs my memory, to mate with the rubber connector.
Swarfy.