318 exhaust manifolds on a 360

Treblig said
The problem is with the bottom of the port. There just isn't enough material there to cut. The bottom of the 318 manifold doesn't have enough material to cover the 360 head's port.

Treblig

I did it on a pair of manifolds that I put on a 74 charger with a 360. Get it as close as you can with what you have to work with.

68 - 70 340 exhaust manifolds would be the best choice if you can get a set.