340 exhaust manifolds

The best flowing combination would be a 70s 340 driver's manifold and a Jeep Grand Cherokee (96/97/98) passenger's side manifold. This would give you the best flow for the lowest price. You can find a Cherokee manifold here:

Car-Part.com--Used Auto Parts Market

You can have it list manifolds by price or distance.
Thanks for all the help. Have bought a set off 512Stroker, on to the next hunt.