72 340 pass side manifold

GSS said
Mine is 3418623 but I don't know that it is original to the car. Outlet inside diameter is 1 7/8". Is there a correct right side 1972 manifold with the larger 2 1/4" diameter?

Nope!! 70 &'71 and up were 1 7/8". If you not going 100 original, I'd swap it for a 96/97/98 Jeep Grand Cherokee passenger's manifold.