I want to know if 318 exhaust manifolds are the same as 73 duster 340 exhaust manifol

[mopar951]

Hi I want to buy a nice exhaust kit I have a 70 duster with 318 exhaust manifolds but the guy is saying his 340 exhaust kit won't fit what's the difference ?

 

[67Dart273]

So far as I know all 340 left side have a "flat face" head pipe connection, and all 318's use a bell connection

Examples of 340: These use a flat gasket

And there are differences in head pipe shape / bend even in the 340s over the years

 

[67Dart273]

One example of a 273/ 318 manifold, note the bell casting. The end of the pipe is belled, with a loose steel formed flange on the pipe. Just like the 340s, the 273's and 318s have differences over the years. Go by casting no. and find out what you have

 

[oldkimmer]

..............As 67 explained, and the flanges are a bigger size on the 340, the 73 340 has a fixed flange on the drivers side, but a bell flange on the pass side.............kim.......

 

[mopar951]

Ok thanks I do have the casting number it's 3614395

 

[67Dart273]

According to this thread it's

http://www.forabodiesonly.com/mopar/showthread.php?t=30326

My Galen Govier white book lists it as

3614395 (cast #)
3614396 (part #)

LH (left hand) 73-74 A-body 318


Note that some casting numbers around the www are WRONG

 

[YY1]

Most local exhaust shops will make you custom head pipes for about $100.
Might be a bit more if you need new ball flanges.

Does anyone know if the 73-74 318 Roadrunners had the 340 manifolds?
I know they had dual exhaust, and were rated 170HP (vs the "normal" 318 w/single exhaust at 150).

 

[pyrojim]

This is a two part question. I think these are 318 exhaust manifolds off a 78 volare? Are there supposed to be heat shields?? Next, can I do away with the butterfly valve??
Thanks

 

[pyrojim]

Butterfly

 

[66fs]

This is a two part question. I think these are 318 exhaust manifolds off a 78 volare? Are there supposed to be heat shields?? Next, can I do away with the butterfly valve??
Thanks

Looks like a set of 64-66 A body manifolds by the numbers. I take out the butterfly, shaft and all, and tap the manifold for bolts. It will warm up slower but it can never stick shut. Maybe a bit more flow. Pre smog, no shields.

 

[pyrojim]

Looks like a set of 64-66 A body manifolds by the numbers. I take out the butterfly, shaft and all, and tap the manifold for bolts. It will warm up slower but it can never stick shut. Maybe a bit more flow. Pre smog, no shields.

That's what I figured. Thanks, I appreciate it.