318 vs 340 exhaust manifolds

This article must be old because I didn't see them try the 98 -02 Magnum truck manifolds. The magnum manifolds came with 2 1/4" exit hole. The hole at the head exhaust port is gigantic. When I tried to port my 302 casting heads to match the magnum manifolds it was impossible, the hole in the manifold was just too big. The motors that these manifolds came on in 98-2002 put out 250 HP and that was restrictive catalytic converters and smog ports. I wonder how much horse power they could handle. I have a passenger magnum manifold on my "69 Barracuda (fit like a glove), they only cost $60 on ebay. I scrounged statewide craigslist and found a 340 driver's side for $150.

The gasket in "blue" is 318, the full length gasket is 360. The 360 almost swallows the 318 gasket, maybe 20 or 25 percent more flow???!!!
Seeing is believing,,,see pics


Treblig