Topic: C7OE-C 390 GT exhaust manifold- passenger side

[preaction]

When was the C7OE-C passenger side exhaust manifold first put in service (about) to replace the C6 version for the 390 GT. So it seams I answered my own question or I may have a manifold from another model car ?the date on my C7OE-C is 7c12 which fits the build of the car. It seams the valve I have fits being used in the 67 orientation; with the wheel of the valve towards the right hand wheel of the car. I am not sure what parts are correct for the build date, any help identifying what is what would be much appreciated thanks Paul. I threw in some pics too. The pics of the manifold in the car show a larger boss on the right side of the manifold (larger than a C6 part) that interfears with the valve.

[midlife]

Just curious...what was the purpose of the valve?  I can't imagine shutting down the exhaust route for any reason...

[BKnapp]

I think the purpose was to heat the air in the intake by staying closed until normal operating temperature, at which point it would stay open.

[preaction]

Bill, you are correct it aids in warming the engine up faster and the by engine heat turns its self off. When I first put the car together I thought I didn't want anything blocking the exhaust but this helps make the car run better and much better driveability.

[preaction]

Is it possible to have a late april build from Dearborn to have been built with a exhaust control valve with the weighted wheel of the valve facing the engine/transmission as the 68 manufactured cars had and not facing the passenger side fender ? Im still a little confused about this as the passenger side manifold date code fits my build very well but is shaped for the 68 style installation.

[RoyceP]

The exhaust control valve was used until the end of 1967 production, in fact it was used through the middle of 1968 production too. I don't think the C6 exhaust manifold was ever correct for Mustang / Cougar, it might fit but it is actually for a Fairlane / Comet application.

Is it possible to have a late april build from Dearborn to have been built with a exhaust control valve with the weighted wheel of the valve facing the engine/transmission as the 68 manufactured cars had and not facing the passenger side fender ? Im still a little confused about this as the passenger side manifold date code fits my build very well but is shaped for the 68 style installation.

[BKnapp]

The exhaust control valve was used until the end of 1967 production, in fact it was used through the middle of 1968 production too. I don't think the C6 exhaust manifold was ever correct for Mustang / Cougar, it might fit but it is actually for a Fairlane / Comet application.

I need to re-verify, but my notes indicate my passenger side exhaust has casting number C6OE 9340 dated 6K5. It does have the weighted/wheel style control valve and everything seems to fit and function properly. I actually don't think the C7OE-C was used for the passenger side until late 68 production (according to Mustangtek).

[preaction]

I need to re-verify, but my notes indicate my passenger side exhaust has casting number C6OE 9340 dated 6K5. It does have the weighted/wheel style control valve and everything seems to fit and function properly. I actually don't think the C7OE-C was used for the passenger side until late 68 production (according to Mustangtek).

  I see and hear what you are saying Bill, the C7-C manifold on my engine is dated 7C6, March 6 1967 and it matches the rest of the dates.

[BKnapp]

Sorry, Paul. I edited my previous post to reflect my understanding the C6OE-A was used in response to Royce's comments. Perhaps Royce meant the C7OE - C was never correct for a Mustang.

Everything I have found indicates the C6OE-A was used until 2/15/68. If the C7's did start getting used in Mustangs in Feb 1968, it would be hard to believe one accidently made it into a car built in April 67; but I have read a lot of strange things happened over this model year. Perhaps a PO "restored" your car with manifold off of a Fairlane, and felt the casting date made it a good fit?

I also recall reading of two different style exhaust valves...one with a wheel like you have shown. Another with an arm that looks it  may require less clearance. All I can tell you is what I have been reading, as I am in the same boat you are.

Good luck...I will let you know if I come across any new info. fwiw, Mansfield does have the C6OE - A, but they aren't cheap.

[RoyceP]

Bill you are right and I was wrong! The MPC - I just checked - verifies what you are saying, the C60Z 9430-A manifold was used on the RH side through February 14, 1968. The C80Z 9430-B manifold began to be installed on the line on February 15, 1968.

Bear in mind these are part numbers, not casting numbers.........

I need to re-verify, but my notes indicate my passenger side exhaust has casting number C6OE 9340 dated 6K5. It does have the weighted/wheel style control valve and everything seems to fit and function properly. I actually don't think the C7OE-C was used for the passenger side until late 68 production (according to Mustangtek).

[preaction]

Thanks for the reply Bill I want to reinstall the engine exhaust control valve with the wheel facing the passenger fender so I will find a C6 manifold and hold onto the c7 part for a future trade.