340 Exhaust Manifolds on Early A-Body??

Wow, that is good news!! Thanks for all your troubles, I really appreciate it. So to recap what it takes to make this work.
1) 98-2003 Durango manifolds
2) raise the drivers side approx. 1/2"
Too easy, LOL
I would guess that the Durango manifolds flow much better than the old restrictive 273's