Magnum manifolds on a 66 dart

There are two sizes of outlets on them. 1-7/8 and 2-1/8. The latter come from trucks, vans and certain year (96ish?) Jeep Grand Cherokee. The JGC gets you the passenger side wide opening and in my case, a van got me the drivers side. The JGC drivers side won't work because the starter location for them is on the other side so the EM rides too tight to the engine. The biggest problem is the narrow engine bay. You'll likely need to shave the drives side down or shim the motor mounts. Steering column is also known to get in the way so that might need to be dealt with as well. In most cases it seems the pass side is "OK" but occasionally needs the casting numbers ground to get just that much clearance.