340 exhaust manifolds

[RUNCHARGER]

Lots of the original ones are cracked, so the repro ones don't seem like too bad of a buy.

[autoxcuda]

Are the original 73 340 manifolds big port log style on both sides OR hipo style w/ cast in heat stove flange on drivers and log on passenger side.

The 72-74 340-360 ebody cars originally have air cleaners with heat stoves.

[Topcat]

They are reproduced...

https://www.yearone.com/Product/chrysler-a-body/ae340

For 50 bucks less from Shakerhood.com

Before Ben passed away, he told me he was the one responsible getting them reproduced.

Correct - buy them from the source!

http://www.shakerhood.com/products.php?id=ExhaustManifolds

I just wanted to verify what you said is true is why I posted.   

[nsmall]

@6bblgt @rocketresto

Thanks for the offer rocketresto.  I'll consider.  Considering headers also.

Not sure how much of a difference 68 - 70 manifolds are vs 1973.  Is there any actual data on this as I do want more flow since I have a fairly High Performance 340.

6bblgt.... Based on the numbers you posted my passenger side is a 73 340...but the driver side I can't confirm even though I think it was only like one number off of what you posted.


Pic number one is driver side.


Thanks

[6bblgt]

casting numbers are usually different than part numbers (often by just one)
I didn't have the casting number for the 1973 LH manifold - THANKS!!

1973 e-body 340 casting numbers:
RH = 3418623 (part # 3418624)
LH = 3751084 (part # 3751083) - also used on '74 360s

casting number represents the part "as cast", part number represents the part "as needed for assembly" after machining/chroming/painting or any other operation a part may need

some casting numbers can be used for more than one final part number, mid-'70s 440 intake manifolds come to mind

[nsmall]

@6bblgt @rocketresto

Thanks for the offer rocketresto.  I'll consider.  Considering headers also.

Not sure how much of a difference 68 - 70 manifolds are vs 1973.  Is there any actual data on this as I do want more flow since I have a fairly High Performance 340.

I'm glad I have 340 manifolds but I'm still debating the header situation.  Not sure it's worth all the money and time but I do like horsepower.

Thanks 6bblgt for confirming I have 340 manifolds.

[moparmadman69]

@6bblgt @rocketresto

Thanks for the offer rocketresto.  I'll consider.  Considering headers also.

Not sure how much of a difference 68 - 70 manifolds are vs 1973.  Is there any actual data on this as I do want more flow since I have a fairly High Performance 340.

6bblgt.... Based on the numbers you posted my passenger side is a 73 340...but the driver side I can't confirm even though I think it was only like one number off of what you posted.


Pic number one is driver side.


Thanks

Those are correct 340 manifolds for a 73-74 340/360 HP motor. Unlike the 70 style (549-553) these are a 2" ball flange manifold. That means the largest pipe you can run off those manifolds is 2.00". The factory head pipes were 2.00" off the manifold with a loose flange and once they got under the car the remainder of the head pipe was 2.25". The 70 style have a 2.50" fixed welded flange which usually will accommodate 2.25" exhaust all the way back which is sufficient flow for a 340. You can always add high flow mufflers like our Magnums and it will accommodate more HP. Just sayin 

[Topcat]

@6bblgt @rocketresto

Thanks for the offer rocketresto.  I'll consider.  Considering headers also.

Not sure how much of a difference 68 - 70 manifolds are vs 1973.  Is there any actual data on this as I do want more flow since I have a fairly High Performance 340.

but I'm still debating the header situation.  Not sure it's worth all the money and time but I do like horsepower.

Headers require more maintenance overall.
They heat up the floor boards and front cabin alot more.
Gaskets blow out and then you get that annoying header leak sound. 
All rubber and plastic parts take a beating from the additional heat they put out.
More decibels entering cabin while accelerating. After a while it gets to be too much for a long drive.
Ground clearance with most brands are a major problem. TTI headers have the best clearance but are very expensive.
One pipe goes under the idler arm. I call this the speed bump pipe. It never fails: one high spot on the road and Bam! Game over!

Headers will definitely make more power but at what cost? Peace of mind?

http://www.hotrod.com/articles/mopp-0106-manifolds-vs-headers/

[nsmall]

@6bblgt @rocketresto

Thanks for the offer rocketresto.  I'll consider.  Considering headers also.

Not sure how much of a difference 68 - 70 manifolds are vs 1973.  Is there any actual data on this as I do want more flow since I have a fairly High Performance 340.

6bblgt.... Based on the numbers you posted my passenger side is a 73 340...but the driver side I can't confirm even though I think it was only like one number off of what you posted.


Pic number one is driver side.


Thanks

Those are correct 340 manifolds for a 73-74 340/360 HP motor. Unlike the 70 style (549-553) these are a 2" ball flange manifold. That means the largest pipe you can run off those manifolds is 2.00". The factory head pipes were 2.00" off the manifold with a loose flange and once they got under the car the remainder of the head pipe was 2.25". The 70 style have a 2.50" fixed welded flange which usually will accommodate 2.25" exhaust all the way back which is sufficient flow for a 340. You can always add high flow mufflers like our Magnums and it will accommodate more HP. Just sayin 

@moparmadman69

Ughhh.  Im getting ready to have my new exhaust installed and I thought I had 2.25 inch exhaust coming off my 1973 340 exhaust manifolds.  You state above this is NOT possible.  Ughhh.  I guess I need to drop some more money as 2 inch is to narrow for what I'm trying to do.  When I measure it.... it seems like 2.25.  Sorry to question you, but are you 100% certain?

Thanks

[1 Wild R/T]

Another option that works well is 5.9 Magnum truck manifolds....

[nsmall]

I have TTI headers....1 and 5/8 that have 3 inch collectors.

I guess the question I'm trying to ask is.....is stock exhaust 2 inches on a 1973 340 Ebody?

Darren....you copy?   @Burdar

[YellowThumper]

If you are in a pinch to ge it together. Use your current manifolds with the 2 inch. Then right after the connection have pipes expanded to the diameter you want run to the back. With a functional system you can then decide where to go afterwards. Headers or time to search for manifolds of choice. You only then have to change out the head pipe.

My2c Mike.

[Burdar]

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.

[Chryco Psycho]

It was actually proven to increase power the other way around with larger pipes off of the manifolds & reducing toward the tips as the exhaust cools

[moparmadman69]

@6bblgt @rocketresto

Thanks for the offer rocketresto.  I'll consider.  Considering headers also.

Not sure how much of a difference 68 - 70 manifolds are vs 1973.  Is there any actual data on this as I do want more flow since I have a fairly High Performance 340.

6bblgt.... Based on the numbers you posted my passenger side is a 73 340...but the driver side I can't confirm even though I think it was only like one number off of what you posted.


Pic number one is driver side.


Thanks

Those are correct 340 manifolds for a 73-74 340/360 HP motor. Unlike the 70 style (549-553) these are a 2" ball flange manifold. That means the largest pipe you can run off those manifolds is 2.00". The factory head pipes were 2.00" off the manifold with a loose flange and once they got under the car the remainder of the head pipe was 2.25". The 70 style have a 2.50" fixed welded flange which usually will accommodate 2.25" exhaust all the way back which is sufficient flow for a 340. You can always add high flow mufflers like our Magnums and it will accommodate more HP. Just sayin 

@moparmadman69

Ughhh.  Im getting ready to have my new exhaust installed and I thought I had 2.25 inch exhaust coming off my 1973 340 exhaust manifolds.  You state above this is NOT possible.  Ughhh.  I guess I need to drop some more money as 2 inch is to narrow for what I'm trying to do.  When I measure it.... it seems like 2.25.  Sorry to question you, but are you 100% certain?

Thanks

The issue is that since is a ball and socket style manifold you can't get enough flair on the pipe to get a seal. For what you are trying to achieve I would suggest the 70 style manifolds with an oil filter adapter would be your best bet.