Stay tuned, the magnum exhaust manifolds from a Durango are enroute from HemiEd and I will be heavily documenting their mods and installation on my 70 Dart(orig. /6 with TransDapt /6 to 360 motor mounts). Im hoping there are a lot of guys who will be helped by this. Im sure that I'm not the only one who is interested in inexpensive high flow factory exhaust manifolds that are readily available either new or used that fit with minimum modifications for a fraction of the price of 340 manifolds. I saw an article that 340 manifolds flow only well enough to make 11 more horse power on the dyno than standard v8 manifolds(a body manifolds). Magnum manifolds were designed to have high flow rates. In fact if I'm correct, 92-93 Magnum manifolds have a 2 1/2 outlet and following years have a 2 1/4 outlet.. I MIGHT not be all that far off by saying that magnum manifolds flow almost as well as 340 manifolds