mopar big block high performance manifolds ?

[Douglas]

mopar big block high performance manifolds ? can someone chime in here on these. i currently have stock manifolds and wanted to know more about the stock hp manifolds instead of headers on my 67 fury.

 

[1970FuryConv]

For 1969 log manifold outlet diameter was 2.00". HP exhaust manifold outlet diameter was 2.25"
HP exhaust manifolds have better shape and flow IMO.
Because of the up sweep to HP manifolds, they will burn valve cover paint if a barrier gasket is not used. Exhaust manifold gasket MS 90425 will prevent.
Also, HP exhaust manifolds require a special bolt kit to install. They look cool when done. Hadn't learned my lesson about MS90425 when I took these photos

 

[CBODY67]

There were also some OEM orange silicone valve cover gaskets from Chrysler too. Heat shield is a good idea, on the rh side.

CBODY67

 

[Douglas]

There were also some OEM orange silicone valve cover gaskets from Chrysler too. Heat shield is a good idea, on the rh side.

CBODY67

thank you

 

[HOT FURY]

mopar big block high performance manifolds ? can someone chime in here on these. i currently have stock manifolds and wanted to know more about the stock hp manifolds instead of headers on my 67 fury.

Here is a link from tti for factory exhaust manifold casting numbers and applications. I would try to find some of the ones like I have with the 2.5" exhaust flange (PN 2951865 & 2899879) for the best flow depending on what kind of HP your motor has. I took mine and had them baked to release all of the oils, media blasted, then coated with a thermal insulating coating called zybar(similar idea to ceramic insulating coating but this product seems to be more durable and have a higher max temp rating). Make sure if you have someone coat them to get them coated inside and out as best as possible. It helps significantly and you shouldn't need the heat shield but likely plug wire insulating boots.


https://www.ttiexhaust.com/Classics-Ex/MfdCastingNo-383.pdf

 

[HOT FURY]

Dante's has the HP manifold install bolts too btw

 

[1970FuryConv]

Here is a link from tti for factory exhaust manifold casting numbers and applications. I would try to find some of the ones like I have with the 2.5" exhaust flange (PN 2951865 & 2899879) for the best flow depending on what kind of HP your motor has. I took mine and had them baked to release all of the oils, media blasted, then coated with a thermal insulating coating called zybar(similar idea to ceramic insulating coating but this product seems to be more durable and have a higher max temp rating). Make sure if you have someone coat them to get them coated inside and out as best as possible. It helps significantly and you shouldn't need the heat shield but likely plug wire insulating boots.


https://www.ttiexhaust.com/Classics-Ex/MfdCastingNo-383.pdf

Are those #s 2.5" ID exhaust outlet?

 

[Douglas]

Here is a link from tti for factory exhaust manifold casting numbers and applications. I would try to find some of the ones like I have with the 2.5" exhaust flange (PN 2951865 & 2899879) for the best flow depending on what kind of HP your motor has. I took mine and had them baked to release all of the oils, media blasted, then coated with a thermal insulating coating called zybar(similar idea to ceramic insulating coating but this product seems to be more durable and have a higher max temp rating). Make sure if you have someone coat them to get them coated inside and out as best as possible. It helps significantly and you shouldn't need the heat shield but likely plug wire insulating boots.


https://www.ttiexhaust.com/Classics-Ex/MfdCastingNo-383.pdf

thank you great info

 

[HOT FURY]

Are those #s 2.5" ID exhaust outlet?

yes, although since cast when I actually measure them they were about 1/8" smaller diameter

 

[mr gtx]

somebody tested the log manifolds vs hp manifolds and only a few HP difference. I think the 2.5 inch vs the 2.25 inch log manifolds outlets help more than the design.

 

[Douglas]

thank you

 

[AL_Brad]

Because of the up sweep to HP manifolds, they will burn valve cover paint if a barrier gasket is not used. Exhaust manifold gasket MS 90425 will prevent.
Also, HP exhaust manifolds require a special bolt kit to install. They look cool when done. Hadn't learned my lesson about MS90425 when I took these photos

I have the same manifolds (yet to install). They have the MS90425 gaskets on Amazon for $15. Where did you find the bolt kit. I know a couple of longer bolts are needed. TIA.

 

[1970FuryConv]

I have the same manifolds (yet to install). They have the MS90425 gaskets on Amazon for $15. Where did you find the bolt kit. I know a couple of longer bolts are needed. TIA.

I bought HP Fastener Set 8065C, c-body: Tom Hergert, 6901 128th Ave SW, Olympia, WA 98512. 7 nuts, 3 long and 2 short bolt head nuts, 12 studs, Rocket Restorations

Looks like Dante's has same kit
DMPS-6901-8065C Mopar Exhaust Manifold Hardware Kit 1968-71 C-body 383/440 HP - dantesparts.com