72 340 pass side manifold

66fs said
The "bell" is larger on the 360/340 PS exhaust manifold, otherwise it comes out the same. I had an exhaust shop modify my Commando exhaust so I could use it with the 72 340 PS manifold. I'd run the your 318 manifolds. We put 72 340 manifolds on our 73 Dart, 318. Not much difference if you are running a decent set of dual exhaust and a relatively mild cam and 4 barrel carb.

Aren't the ports larger on the 340 exhaust manifolds? Could be a problem sealing against the smaller ports of a 318 head. I think the 340 manifold's passages are larger, too. But I agree, in any event very little if any difference on a mild 318. Not worth swapping.