More exhaust manifolds

DionR said
Interesting. So they pulled the manifold in towards the head when they added the heat stove. Wasn't aware of that. I thought the only difference was the flange for the stove.

You are aware that the '74 360 Duster used the same manifold on the driver's side as the '72 and '73 340 right? You keep saying "340 manifold", just making sure I understand what you mean.

Here is a link to a set of manifolds off a Dart Sport with a casting date of 1-15-74 and the same casting number as the '72 and '73 340 manifold. He claimed it had a 2 1/4" outlet, but no picture. I only offer it as proof they were still casting the same manifold as late as '74.

Well you have a few questions here and I want to make sure I don't confuse you with a wishy washy answer. The late 60s 340 "Large hole" driver looks like it sweeps up quicker and higher than the 70s 340. So, in reality the late 60s 340 was designed so that it was closer to the head/engine where the 70s 340 pulls away from the engine (for the heat shield). This is why the late 60s 340 driver should be more likely to fit the Early As with less interference. If you look at the pics I posted (with the long straight edge) you can see that the late 60s 340 is designed so that it sweeps toward the engine and further up and over everything. If you look closely you can also see that it has a flat section where it goes past the steering shaft while the 70s actually has a hump. This is one of the areas that early As have a problem with (clearance on the steering shaft). With the late 60s manifold there is no hump to hit the steering shaft. Since it rises up quicker and is a little thinner it should also clear the steering box easier.
As for your other question about the link you posted....I have found that they continued to make (manufacture) the 340 manifolds into the 77/78 time frame so, yes, you will see 74/75/76 casting dates on the large hole (2 1/4" ) 340 manifolds. In the link you posted you see two manifolds (L & R). although the seller says that the passenger manifold is 2", in reality it's only 1 7/8". The passenger 340 in the "link" is a 340 manifold but Mopar made many, many 340 manifolds that were only 1 7/8" exit hole. I've never seen a 2" 340 manifold except the ones I "machined" out to 2". I've had many (have some now) of the 1 7/8" 340 manifolds, Members with early As like to use them as they flow better than the stock 1 5/8" manifolds and they are small and fit easier also.

PS - When I say 340 manifold, I'm talking about manifolds that were made for the 340 engine. Some have a 2 1/4" exit and some have a 1 7/8" exit. Many "ebay" sellers love to sell the large hole 340 driver matched with the small hole 340 passenger. It's an easy way to make money because the 340 small hole manifold really isn't worth that much so they sell the small hole with the large hole and are telling the truth when they advertise "340 driver and passenger manifold for sale". I have a small hole 340 manifold for sale right now on FABO but I advertise it as such and sell it much, much cheaper than the large hole manifold. Sometimes I have to buy the mismatched pair just to get a good large hole 340 driver to match with one of my 360 (2 1/4") magnum manifolds.
The first two pics are of another small hole 340 manifold. The last pic is the "REAL DEAL" pair of 340 "Large Hole" driver and passenger manifolds. These "REAL DEAL" 340 manifolds sell all the time on ebay for 600/700 dollars. This is why I came up with this alternative..a large hole 340 driver paired with a large hole magnum for only $320. You can see the big difference in the shape of the large hole 340 passenger and the small hole 340 passenger.
Hope I answered all your questions!!

treblig