HP Exhaust Manifold?

[1966er]

Was there ever a HP Exhaust Manifold for the early 273/318 in a B body? I want to increase exhaust flow but don't want to go the header route. I plan on doing some pocket porting & milling to my otherwise stock heads.

What I did to my 66 Mustang 289, was use factory HP manifolds and did see a great increase in HP.

If not, will 340 HP manifolds fit my 66 Coronet 273 and still be able to use my new exhaust I put on already? Do they dump out in the same location?

I know there was a change on the 273 heads in 1966, but I think it was only on the intake side. Is that correct? If so, can I use any newer MOPAR or after market 4 barrel intake?

I started out with MOPARS many years ago, so I have a lot of catching up to do on what fits what on engines. I know what works with chevys & fords, but not MOPARS.

Keep in mind that back in the day, we (shade tree mechs) didn't have the knowledge on swapping engine parts and doing strokers & such.

thank in advance, steve

 

[tallhair]

Was there ever a HP Exhaust Manifold for the early 273/318 in a B body? I want to increase exhaust flow but don't want to go the header route. I plan on doing some pocket porting & milling to my otherwise stock heads.

What I did to my 66 Mustang 289, was use factory HP manifolds and did see a great increase in HP.

If not, will 340 HP manifolds fit my 66 Coronet 273 and still be able to use my new exhaust I put on already? Do they dump out in the same location?

I know there was a change on the 273 heads in 1966, but I think it was only on the intake side. Is that correct? If so, can I use any newer MOPAR or after market 4 barrel intake?

I started out with MOPARS many years ago, so I have a lot of catching up to do on what fits what on engines. I know what works with chevys & fords, but not MOPARS.

Keep in mind that back in the day, we (shade tree mechs) didn't have the knowledge on swapping engine parts and doing strokers & such.

thank in advance, steve

Don't know if this will help or is more than you want to spend but these from CL might be a good fit for you. However, I'm not a small block guy but they are probably pretty damn near the best thing you would find in small block factory manifolds for the money. Ports might be larger than your heads ports ... maybe someone can speak to that. As far as bolting up to your new exhaust, a exhaust shop could handle that pretty easily.

http://stlouis.craigslist.org/pts/3652517177.html

From STL area CL

Mopar 340 Exhaust Manifolds - $225 (Cedar Hill)

​

Factory original set of manifolds casting numbers 3418623-1 and 3418621-1.Date codes show 2-2-71 & 3-8-71. No Cracks,Never Welded. Gasket surface looks pretty decent for good seal.Heat riser flap has been removed. These casting numbers are listed for both Dodge and Plymouth 1971 B-Body and E-Body Mopars with the 340.Includes Cuda Challenger Charger RoadRunner Satellite and GTX.Also listed for other years and models. If you know what these are, you know this is a reasonable price. I have had these for years for a project I never got around to doing and it will not bother me to keep them years longer, so don't bother low balling me and no I am not interested in any trades. If interested call or text NUMBER OMITTED BUT IT'S IN THE AD

 

[1966er]

Don't know if this will help or is more than you want to spend but these from CL might be a good fit for you. However, I'm not a small block guy but they are probably pretty damn near the best thing you would find in small block factory manifolds for the money. Ports might be larger than your heads ports ... maybe someone can speak to that. As far as bolting up to your new exhaust, a exhaust shop could handle that pretty easily.

http://stlouis.craigslist.org/pts/3652517177.html

From STL area CL

Mopar 340 Exhaust Manifolds - $225 (Cedar Hill)

​

Factory original set of manifolds casting numbers 3418623-1 and 3418621-1.Date codes show 2-2-71 & 3-8-71. No Cracks,Never Welded. Gasket surface looks pretty decent for good seal.Heat riser flap has been removed. These casting numbers are listed for both Dodge and Plymouth 1971 B-Body and E-Body Mopars with the 340.Includes Cuda Challenger Charger RoadRunner Satellite and GTX.Also listed for other years and models. If you know what these are, you know this is a reasonable price. I have had these for years for a project I never got around to doing and it will not bother me to keep them years longer, so don't bother low balling me and no I am not interested in any trades. If interested call or text NUMBER OMITTED BUT IT'S IN THE AD

Ok....thanks...

- - - Updated - - -

anyone else have any input?

 

[RustyRatRod]

I don't think there was ever an HP manifold for the 273, period. I know that's been a point of contention with the A body guys. Because they think that bastard lookin driver's side manifold that points back is a sign of HP manifolds, and it's not. That's how they all were. I think the only HP "manifolds" ever offered on the 273 was on the D Dart and they were headers made by Doug Thorley. I believe even the 273 Commando had the regular manifolds. Some may argue that, but I think it's correct. And there's absolutely zero reason to have ever offered an HP manifold for the 273 in a B body. I mean really.

Here's the driver's side A body manifold everybody thinks is an HP, but you can plainly see the ball mount. All the ball mount manifolds had small outlets.

 

[Meep-Meep]

The ONLY small block HP manifolds that I know of came on the 340. But even the drivers side looks like the standard up swept 318 style. I think it's just larger is all.

 

[RustyRatRod]

Well, they DID put some HP manifolds on the Dakota R/T, but I don't think we were talkin about the later stuff.

 

[Powerflite]

I was going to suggest using dakota manifolds. I believe they flow as well as 340 manifolds and are a lot cheaper. I run them on my '70 Satellite. They dump closer to the floorpan, at the rear; but it works out well.

 

[RustyRatRod]

They do, especially the ones with the 2.125" outlets that came on the early 90s Dakota R/T and Rams.