273 manifolds

One guy I talked to that used Durango/Dakota stock manifolds had to shim his engine mount.

Actually, here's his email....

98-02 Durango/Dakota (approximate dates, I am not exactly sure) 318/360 exhaust manifolds will fit. They are higher flow than the original 273's (which I liken to pooping through a cocktail straw) or the 340 types. The benefits are a balanced flow between the manifolds. The stock 273 drivers side manifold is highly restrictive due to several harsh curves and the compressed area where it goes around the starter. 2 1/4 to 2 1/2 inch collectors will bolt right up.

The only mods necessary are of course new down pipes, different length mounting bolts and possibly you might have to shim the motor mounts as much as 1/4" to safely clear the steering box. Mine cleared no problem. Power steering will not work though. Some people have had to dimple about an inch at the point where the firewall transitions to the floorboards on the passenger side to allow the down pipe to clear without heat transfer problems. I simply spliced in a pipe with a 30 degree curve off of a donor car.
I have a 4 speed manual so clearance was tight in the torque shaft (z-bar) area, so I routed the pipe OVER and down past the starter . Otherwise I would have had to oval the pipe to pass between the block and starter...... which would have restricted the flow.
These manifolds are plentiful on Ebay. I paid $35 for my pair.

Clearance, although tight is no where as tight as it appears here. The steering box clears by at least 3/8 an inch at the tightest point. (Below the center ports). The manifold does not touch the steering shaft, even though it looks like it. I also ground a little off the steering U joint just to be safe. Oh, three on the tree will not work either.

Spitfires are problematic and the new versions don't fit right, if you can even find them. One guy I talked with had them and they were leaking at some of the welds. I'm going with the 340 manifolds, although they are really expensive, I've got one half and got a lead on the other half for a decent price. See my other post in another topic about this. This guy here ->http://www.ultrajosh.com/resources/ has done the 340 thing, click on exhaust in his left menu. Or go here ->http://www.ultrajosh.com/myshop.htm to see photos.

340 HP Manifolds