1974 Duster

Looks like classic manifolds will not work with the magnum engines due to port mismatch, questions-

1) does anyone make a-body magnum headers?

2) are all magnum manifolds the same configuration? jeep vs truck/durango.

Not sure if anyone makes what you're looking for or about other manifolds that will work. However, you could make your own headers - I think Summit or someone sells a kit. It's on the pretty hard scale to do (never done it myself - but saw it done by a friend of mine some years back) you need the plate that bolts up to the head and a ton of bent and straight header pipes. If you go with 3/8" plate they wont warp. You could get the flat stock, scribe out the holes from the manifold gasket and grind till you get it right - drilling the bolt holes, or have the plate water jetted. Then with the motor in the frame start piecing the pipe on (tack welds) till you get what you want and then take to a pro that has the best equipment to complete the job correctly. Then, have them ceramic coated. It's a ton of work and not real cheap to have done, but your alternatives are restricted by lack of engine and body type match.