400 Manifolds.. What is the difference .....

[TruckDriver]

How do you tell the difference between the regular exhaust manifolds and HP manifolds? Anyone have pics of the difference?

[694spdRT]

I asked this in an earlier post. If you look and Nacho's recent thread you can make out what they look like. The driver side swoops up like the earlier versions and the passenger side seems to be lower and hug the block closer. That is the main one I have had a question on as well.

[TruckDriver]

Ok, I did a search and I musta over looked it. But basically, if they are arched up in the center, they are the HP ones?

[694spdRT]

That applies for the earlier HP models. I am still trying to determine on the later passenger side HP manifold how much of a rise there actually is. I don't believe it has the same look as the earlier ones...more of a smoother top maybe. I found a matched set in a van at a junkyard and it has a HP driverside but the passenger side one does not look like the older casting. If someone has a pic of one off the engine would be great.

[Nacho-RT74]

as far I know, same look, only differences on exhauts pipe flage hole bolts. I think that I have an extra pair rounding. When I get again in my hands the Dig cam will post a pic.

[8WHEELER]

These are mid 71 date coded manifolds I sold 3yrs ago, they are a matching set. The ribs and
the small holes for the heat shield tell you right away they were 71 and up.

Dan

[TruckDriver]

My next question is, did they come on 2bbl cars too? Cause those look like whats on my car.

[694spdRT]

Thanks for the pics Dan.

[Nacho-RT74]

the passenger side doens't looks like mine but I have to check... Mine doesn't have the "heater valve" spring and stuff or whatever it calls.

My passeneger side is more "rounded" or "arched" on top than the posted one. That looks like a standart one that I also have, a pair of those ready to trash

[694spdRT]

Hmmm...the mystery continues. 

[Nacho-RT74]

Sorry that I can't help right now with pics... but will do

[Charger_Croatia]

My next question is, did they come on 2bbl cars too? Cause those look like whats on my car.

I couldn't have a look at mine earlier but I'm with you DodgeChargerGuy. 
Maybe former owner have replaced them to HP ....

Any use of number from passenger side exhaust?     

[AKcharger]

That Passanger one is a 2 bbl manifold, the 4 bbl/HP had a high arch. kind of like this one from ebay

[694spdRT]

OK, this is a passenger side manifold from a '71 Charger R/T. Is this what the later manifolds looked like? It sure looks the same as the earlier ones and I thought the later ones were different.

[Nacho-RT74]

THAT ONE  is like mine BUT without the warming valve/spring or whatever it calls stuff...

My driver side is like the first one posted, not like AK did.

I still think only difference throught the years are the flange holes position to make "hard" to instal one or another years car... rest differences can be just that kind of reinforcements what is not a big deal to install on any car

[694spdRT]

Hi Nacho,

So it basically looks like my '69 manifold? Here are some pics...the original valve has been removed from mine and brazed shut.

[8WHEELER]

I thought the 71 and up manifolds HP or non HP all had ribs on them? all the originals I have seen did.
Yes they also change the flange bolt pattern to header pipe, 71 and up will not bolt to 68 or 69 without
changing the header pipe. Then the C-Bodys are different yet.

Dan

[TruckDriver]

My car has the high arched one one the drivers side, and the straight one on the passenger side. To put HP ones on my car, do I have change both or can I just change the passenger side manifold?

[8WHEELER]

You can replace just the RH side, but the flange may not have the same bolt pattern, depending
on the year of the manifold.

Dan

[Nacho-RT74]

Hi Nacho,

So it basically looks like my '69 manifold? Here are some pics...the original valve has been removed from mine and brazed shut.

Yes, that's how mine looks, same as your engine has.

[RD]

My car has the high arched one one the drivers side, and the straight one on the passenger side. To put HP ones on my car, do I have change both or can I just change the passenger side manifold?

I have a pair of date code correct 72 exhaust manifolds if you would like them.  pm for details.

[Charger_Croatia]

THAT ONE  is like mine BUT without the warming valve/spring or whatever it calls stuff...

OK, one dumb question: that "stuff" is needed for what ?? I mean will it be better to take it off or leave it on place??

[694spdRT]

THAT ONE  is like mine BUT without the warming valve/spring or whatever it calls stuff...

OK, one dumb question: that "stuff" is needed for what ?? I mean will it be better to take it off or leave it on place??

It helps to warm the engine up faster in cold weather....not much of an issue for me. Especially since I blocked the heat crossover in the intake manifold too. 

[Nacho-RT74]

that valve close that side exhaust and makes the heat/smoke runs throught crossover duct on intake manifold to heat the gas and the rest of engine and make it warm faster as explained above.

That valve is opened by a bimetallic return spring once is warmed siimliar to the one mounted on mainfold to choke.

[RD]

pete,
  here is a pair of non-hp exhaust manifolds.  the top is pass. side. these came off of a 72 dodge monaco, date code 10/71

[TruckDriver]

I went to the car storage today to turn the engine over a few times, Passenger side has the number 3814999, drivers side is 3814400, casting  date 11-17-'71. I thought the driver side was arched more, but I guess not. Guess I need a set of HP's then

[Charger_Croatia]

Thanks for explanation for that "stuff".

And I must say that my driver side is arched more, like on 8WHEELER picture. So now I'm confused. 

I think cudaken got a pair of  74 HP manifolds for me so I'll change them anyway