5.9MAGNUM EXH MANIFOLDS

This is (Stolen) from a forum long ago and I can not give credit to the person.

"Installing Durango/Dakota Exhaust Manifolds in an early A body

This is the unit installed in 360 66 Barracuda. They clear everything by at least 1/4" without mods. The tightest spot is directly below the center ports. Early A-Bodies are sadly neglected by the aftermarket industry so it becomes necessary to create your own exhaust system or pay nearly a $1000 dollars for a set of headers. Durango/Dakota manifolds were an inexpensive and relatively easy choice. The manifold is the same whether it was 318 (5.2) or 360 (5.9). Late 90 units through the early 2000's are best.

Surprisingly enough these exhaust manifolds will fit with some minor tweaking in any 64-66 Dart, Valiant or Barracuda without power steering. The major considerations before attempting this modification are, new collectors and exhaust will have to be fabricated due to the fact that the collectors are in different positions from the original 273 manifolds. And the clearance between the steering box and the center of the manifold will be tight. The steering shaft may contact as well. I had to trim and grind a little bit for good clearance.

The benefits are that the collector pipes can be up to 2 1/2" wide and still mate to the manifold, better exhaust flow is due to the larger "log" and no constrictive flattening of the collector around the starter. I compare the stock units to trying to "crap" through a cocktail straw.

The manifold bolt pattern is the same on any 273 through 360 engine. You will need Dakota/Durango gaskets. If you have a die grinder this would be an excellent time to gasket match your exhaust ports. The ports are a little smaller than the Felpro gaskets I used. New bolts and studs will have to be purchased as the new manifold does protrude farther out.

Regarding clearance, if you have old motor mount rubber, I recommend shimming the mounts at the K frame using fender washers or a steel plate to raise the engine slightly. This may be necessary with new mounts as well. Usually a 1/4" is sufficient, I do not recommend more than 3/4" as the stud on the motor mount will not have enough thread showing to be safe. If it isn't raised it could contact the steering box. This is the tightest clearance. Raising the engine this slight amount will not affect the drive train geometry.

With the thicker profile the passenger exhaust may to too close to the inner fenderwell. I used a 2" diameter steel pipe as a dolly the length of the log and a heavy hammer to make a concave surface. The collectors on both units curve in toward the engine slightly so the collector pipe does not even come close.

Another consideration is the fact that the collectors angle back rather than going straight down. On the passenger side it is important the pipe does not contact the floor board firewall intersection as 40 year old jute padding under the carpet will burn easily. You may find it necessary to dimple the metal at that point slightly and extra insulation is a good idea.

An excellent start to fabricating the exhausts would be to get a larger diameter Y pipe or dual system to section up and reweld it to clear obstructions. I used a Y pipe off of a 78 Diplomat for mine. I also routed the pipe over the starter and then down. Most auto parts stores have exhaust sections that can be welded together in a myriad of configurations as well. However you will need the flanged end of the collector pipe and a like diameter clamp.

With a little ingenuity you will find there are no insurmountable problems to making this modification."