340 exhaust manifolds

[Cudakiller70]

I have a 71 340, went with TTI SHORTYS about the same price as OEM manifolds. TTI's fit very well.

[moparmadman69]

Lots of times, the factory used a smaller diameter pipe right off of the manifolds. Then, once the pipe got past the starter, shift linkage and oil filter, it expanded to a larger size. My guess is that the factory pipe on the manifold was 2". Somewhere along side the trans, it expands to 2 1/4" OD. Most of the system is probably 2 1/4".

I don't see a problem with using a reducer and connecting your headers to a 2 1/4" system since you already have it. Save some money and use your existing system so you can get the car on the road. Then in a couple years, you can upgrade to a 2 1/2" system.

Factory exhaust was 2.00" off the manifolds for about 16" then they went into 2.25" all the way to the mufflers back by the gas tanks and exited the muffler in a 2" tip.