Original Exhaust Manifolds for a 1970 Coronet R/T

[RT70]

I originally posted this thread under "Mopar Exhaust Systems". I got a few answers but still need more information. Since the car is a 1970 B Body; I thought this Forum may have folks familiar with my problem(s)

Original Thread
I have an exhaust problem and I hope some of you Mopar (experts) folks can help me out. I have posted a number of questions over the last year and have got excellent advice from the people on this forum.

I have a 1970 Dodge Coronet R/T, and this is my first Mopar. The engine is a 440 Magnum coupled to a 727 Trans. The engine has headers, and I want to put the original exhaust manifolds back on. I have a number of questions as I am just learning about Mopars.

When I bought the R/T it came with a bunch of parts. There were a set of what looks like the original exhaust manifolds? I have attached a couple photos of the manifolds. The Right Manifold has these numbers on it “12297 2806900”, and the Left Manifold has these numbers on it “1228670 2843992-1”. Are these the correct exhaust manifolds for a 440HP in a 1970 Dodge Coronet R/T, and could someone decode these numbers?

On Sec._11-7, Fig._8, in the 1970 Dodge Coronet Service Manual, it shows an Upper Carburetor Air Heater and a Lower Carburetor Air Heater. These parts did not come with my R/T; do I need to have these parts for my car to operate properly? If I do need these Air Heater parts, where can I find them? In looking for exhaust parts from various Mopar vendors, I saw a “Spark Plug Heat Shield” for #6 & #8 Plugs; is this part needed? I also saw many exhaust hardware mounting kits; anyone have a recommended Mopar vendor for these?

What color should the exhaust manifolds be painted?

The “Heat Control Valve” appears to be in good shape; is there a recommended lubricant?

If anyone has any advice that would make this project go better or problems I might run into; I would appreciate any advice.

Thanks, Richard

RT70, Yesterday at 12:04 PM

 

[moparnation74]

Heat control valve no lubricant...it will just burn off..Personally, I always remove the butterfly and render it useless but cosmetically appears stock...Last thing you want is for it to get stuck closed. I don't see the "wick" that is under the bolt on the topside but they are usually long gone. I am not sure where you can buy the wick only but it comes with a new kit(kits are pricey)...

There are two heat shields the one you mentioned on the passenger side and the other is a single behind plug 7 on the driver side. You can get them from frank badalson..

The new hardware kits are the same vendor so find the cheaper price/shipping from a seller....

Originally the manifolds had NO coating....there are many choices...A good at home is Eastwoods manifold paint.(cast is the color I believe its called)

I get mine ceramic coated inside and out by Performance coatings(satin grey)
http://performancecoatings.com

 

[RT70]

Heat control valve no lubricant...it will just burn off..Personally, I always remove the butterfly and render it useless but cosmetically appears stock...Last thing you want is for it to get stuck closed. I don't see the "wick" that is under the bolt on the topside but they are usually long gone. I am not sure where you can buy the wick only but it comes with a new kit(kits are pricey)...

There are two heat shields the one you mentioned on the passenger side and the other is a single behind plug 7 on the driver side. You can get them from frank badalson..

The new hardware kits are the same vendor so find the cheaper price/shipping from a seller....

Originally the manifolds had NO coating....there are many choices...A good at home is Eastwoods manifold paint.(cast is the color I believe its called)

I get mine ceramic coated inside and out by Performance coatings(satin grey)
http://performancecoatings.com

moparnation74,
thanks a lot, great answers, I think I'll do like you suggest on that Heat Riser Valve (disable it). I didn't realize that #7 spark plug also had a heat shield. When you said you got your manifolds "ceramic coated", is that done for both headers and factory manifolds-also what does the coating do???
You provided me with a wealth of information and I didn't want to question you to no end!!! But one more, do I need to have those "Upper and Lower Carburetor Air heater" assemblies that attach to the driver side exhaust manifold? I was thinking that they probably were to help the engine on cold engine start ups??

Your answers have helped a lot, Richard

 

[moparnation74]

moparnation74,
thanks a lot, great answers, I think I'll do like you suggest on that Heat Riser Valve (disable it). I didn't realize that #7 spark plug also had a heat shield. When you said you got your manifolds "ceramic coated", is that done for both headers and factory manifolds-also what does the coating do???
You provided me with a wealth of information and I didn't want to question you to no end!!! But one more, do I need to have those "Upper and Lower Carburetor Air heater" assemblies that attach to the driver side exhaust manifold? I was thinking that they probably were to help the engine on cold engine start ups??

Your answers have helped a lot, Richard

Justin btw my friend

Correct, it is the same ceramic coat....Those guys are mopar gents in general and provide top notch work at half the price of jett hot coatings and better....They also inspect for cracks etc....Ones you cannot see. One of my sets was super nice and one had a hairline crack. They utilize an old school welder whom repaired it and you cannot tell it at all...and I am picky...

Those heat shields...I would not drill and tap 40 plus year old cast iron at risk to cracking the manifold.

#7 shield below(not mine but an example)

 

[4mayhemi]

I'm a little confused from the two threads, are you still putting in the 68/69 manifolds and going thru the trouble of heat shields, tube and coatings? At that point, if you already have headers and it's running you might as well be patient and get the right 70 manifolds 1865/9879 (with all the choices somebody that got the headers to fit was a job in itself!).
They are pricey and harder to find. FWIW I see as many 68/69 manifolds at swap meets as 14" rallys - a lot. There are a few on epay, but I am personally apprehensive of buying manifolds without seeing them in person because cracks/repairs are easily covered.

 

[RT70]

I'm a little confused from the two threads, are you still putting in the 68/69 manifolds and going thru the trouble of heat shields, tube and coatings? At that point, if you already have headers and it's running you might as well be patient and get the right 70 manifolds 1865/9879 (with all the choices somebody that got the headers to fit was a job in itself!).
They are pricey and harder to find. FWIW I see as many 68/69 manifolds at swap meets as 14" rallys - a lot. There are a few on epay, but I am personally apprehensive of buying manifolds without seeing them in person because cracks/repairs are easily covered.

4mayhemi
The exhaust manifolds that I have came with the car as spare parts. One of my questions was are they 1970 manifolds. You have cleared that up with "they are 68/69 manifolds". The headers that are currently on my 70 R/T make it very difficult to work on it. I'm trying to collect all the necessary parts before installing. I didn't know what parts are needed and not needed; upper and lower carburetor air heaters, spark plug shields, etc. I may of found the carburetor air heaters-have to call, I need to verify that I really need them.

 

[4mayhemi]

I may of found the carburetor air heaters-have to call, I need to verify that I really need them.

Are you running the original Carter AVS and air cleaner assembly, or aftermarket?

 

[RT70]

r

Are you running the original Carter AVS and air cleaner assembly, or aftermarket?

4mayhemi

I have the original AVS Carb & Air Cleaner Assembly.
Richard

 

[4mayhemi]

I have the original AVS Carb & Air Cleaner Assembly.

Surprised to see headers with a Carter dialed in! Usually Holleys/Eddys were common swaps by the time someone thought they needed headers. I'm still debating whether to restore my Carter and use it or not (and I have headers too).

If you're getting the heated air parts to help with a cold start/choke/fast idle down then I see, but if you are trying for originality and scour for shields/stove/pipe you might run into problems mixing years (i.e can 70 heat stoves work with 68/69 manifolds?). Like other posters said, the exit angle is different, and the 70s have cast-in threads so you're not drilling. The heat riser valve is different too. There's probably other differences between 68/69 and 70/71 I'm not aware of. Until then, here's some can-do (read: funny) inspiration for a header setup:

 

[RT70]

Surprised to see headers with a Carter dialed in! Usually Holleys/Eddys were common swaps by the time someone thought they needed headers. I'm still debating whether to restore my Carter and use it or not (and I have headers too).

If you're getting the heated air parts to help with a cold start/choke/fast idle down then I see, but if you are trying for originality and scour for shields/stove/pipe you might run into problems mixing years (i.e can 70 heat stoves work with 68/69 manifolds?). Like other posters said, the exit angle is different, and the 70s have cast-in threads so you're not drilling. The heat riser valve is different too. There's probably other differences between 68/69 and 70/71 I'm not aware of. Until then, here's some can-do inspiration for a header setup:

View attachment 431631

4mayhemi,

I am not going to use the 68/69 manifolds. I decided to get the correct 70 manifolds. Do you think I need the carb air heaters??? I don't drive (rarely) the car in the winter.

Richard

 

[Richard Cranium]

No

 

[4mayhemi]

Long answer:
I had asked above about which carb/air cleaner to see if you had elect choke with a pretty chrome pie tin. Then you definitely wouldn't need it. Years ago I purged mine on my RR when I switched the Carter out, and at that time it then seemed easier to dial in, but that could've been the Carter.

I think the heated air works in combination with the carb choke and idle for more than cold startup. But realize "cold" doesn't mean freezing, its also just the time it takes for the fast idle to kick down so you can start driving after startup in any mid-temperature. The warming carb atomizes the gas quicker, and I am sure it helps emissions somewhat at startup. But that's for daily drivers. You're fine unless you go numbers restore.

Short answer:
RC said it

 

[RT70]

Long answer:
I had asked above about which carb/air cleaner to see if you had elect choke with a pretty chrome pie tin. Then you definitely wouldn't need it. Years ago I purged mine on my RR when I switched the Carter out, and at that time it then seemed easier to dial in, but that could've been the Carter.

I think the heated air works in combination with the carb choke and idle for more than cold startup. But realize "cold" doesn't mean freezing, its also just the time it takes for the fast idle to kick down so you can start driving after startup in any mid-temperature. The warming carb atomizes the gas quicker, and I am sure it helps emissions somewhat at startup. But that's for daily drivers. You're fine unless you go numbers restore.

Short answer:
RC said it

Attached some pic's of my engine/carb, took a while, Richard

 

[RT70]

Heat control valve no lubricant...it will just burn off..Personally, I always remove the butterfly and render it useless but cosmetically appears stock...Last thing you want is for it to get stuck closed. I don't see the "wick" that is under the bolt on the topside but they are usually long gone. I am not sure where you can buy the wick only but it comes with a new kit(kits are pricey)...

There are two heat shields the one you mentioned on the passenger side and the other is a single behind plug 7 on the driver side. You can get them from frank badalson..

The new hardware kits are the same vendor so find the cheaper price/shipping from a seller....

Originally the manifolds had NO coating....there are many choices...A good at home is Eastwoods manifold paint.(cast is the color I believe its called)

I get mine ceramic coated inside and out by Performance coatings(satin grey)
http://performancecoatings.com

moparnation74,

You got your exhaust manifolds coated by "performance Coating"; how are they holding up? Aside from the manifolds looking nice, what are the benefits to the coating?
thanks, Richard

 

[moparnation74]

moparnation74,

You got your exhaust manifolds coated by "performance Coating"; how are they holding up? Aside from the manifolds looking nice, what are the benefits to the coating?
thanks, Richard

As far as holding up that is still undetermined....I have yet to paint the motor. Although I did my research and asked around and got references from them and they have no problems whatsoever. When I had my motor dyne tuned I had them run headers instead of my manifolds. Reason, being initial break in gets very hot and can have backfires which will damage the integrity of the coating. So when the motors gets into the car I will break the manifolds in properly without having to do any engine tuning...

As far as being a better performer...thats subject to debate..but will have better flow and less engine bay heat..

 

[RT70]

As far as holding up that is still undetermined....I have yet to paint the motor. Although I did my research and asked around and got references from them and they have no problems whatsoever. When I had my motor dyne tuned I had them run headers instead of my manifolds. Reason, being initial break in gets very hot and can have backfires which will damage the integrity of the coating. So when the motors gets into the car I will break the manifolds in properly without having to do any engine tuning...

As far as being a better performer...thats subject to debate..but will have better flow and less engine bay heat..

moparnation74,
I'm considering getting this done. To be sure, are they (Performance Coatings) located in Auburn, Wa. This would be good as I'm in Salem, Ore.
thanks for the info, Richard

 

[moparnation74]

moparnation74,
I'm considering getting this done. To be sure, are they (Performance Coatings) located in Auburn, Wa. This would be good as I'm in Salem, Ore.
thanks for the info, Richard

Correct! Really nice group to deal with!
http://performancecoatings.com

If you want pics of mine just let me know....

Justin

 

[RT70]

Correct! Really nice group to deal with!
http://performancecoatings.com

If you want pics of mine just let me know....

Justin

Justin,

If you could post some pic's that would be great,
thanks, Richard

 

[moparnation74]

Justin,

If you could post some pic's that would be great,
thanks, Richard

I will do that this evening

 

[oldbee]

Rt70- RC is correct, those hot air stoves were all about emission control to get quicker heat to carb because it was set up leaner than desirable(ditch them things).