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67 GT500 RH exhaust manifold

Started by Kyle, October 26, 2021, 03:52:56 PM

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JohnB

Quote from: Kyle on October 27, 2021, 02:32:46 PM
Ok thanks for all the information.
I will buy one of those gasket donut from USA and they ship them to me.

Yes I am from Malta.

Kyle

There are shops in Europe that might have it. Let me know.

John

Kyle

Quote from: JohnB on October 27, 2021, 05:09:06 PM
Quote from: Kyle on October 27, 2021, 02:32:46 PM
Ok thanks for all the information.
I will buy one of those gasket donut from USA and they ship them to me.

Yes I am from Malta.

Kyle

There are shops in Europe that might have it. Let me know.

John

I will try to find from UK or Germany.

shelbydoug

I don't understand why that manifold would be used when the CJ manifold was available? You would just use a CJ H pipe with it?

Doesn't make sense for the factory to modify a PI manifold.
68 GT350 Lives Matter!

warwick

The 390 GT manifold was for 14 bolt heads. CJ Manifold was for 16 bolt heads. MPC indicates transition to casting with chamfer for gasket was 2/11/68 (and new H-pipe). Actual cars question that date. A 67 GT 500 with a 428 would have 14 bolt heads.

I think that's the story.

shelbydoug

Quote from: warwick on October 29, 2021, 07:51:26 PM
The 390 GT manifold was for 14 bolt heads. CJ Manifold was for 16 bolt heads. MPC indicates transition to casting with chamfer for gasket was 2/11/68 (and new H-pipe). Actual cars question that date. A 67 GT 500 with a 428 would have 14 bolt heads.

I think that's the story.

That doesn't matter. The lower two holes on the 16 bolt head, on #2 and #3 cylinders are unusable. So Ford stopped drilling them but sometimes can still be found on Service heads.

If a GT right side manifold was used on a 68-1/2 or later 428 instead of a CJ manifold there must be another reason.

I have never seen a 68 W 427 head and I assume that the exhaust bolt pattern was changed to the 14 or 16 BUT having said that, I know as fact that the 67 427 Fairlane manifolds were the old 8 bolt patterns are required access holes in the car to access them.

All FE heads cast after a certain date had the casting bosses for additonal exhaust bolts cast into them, previously cast heads, you can't modify them to the new pattern because the bosses aren't cast into the head.


Again, if this claim is true about Ford modifying the GT casting, that's a head scratchier, UNLESS it is just a supply issue and the CJ manifolds just weren't on the assembly line yet?

I'm not arguing. What is is what is, I just don't see the reason.
68 GT350 Lives Matter!

warwick

I never put one on but my understanding is the 390GT manifold leaks on a 428CJ (early drag cars). The front and rr cyl top bolt is a tad lower w/14 bolt so I don't think you can put both bolts in on pass side rr where top and bottom holes are used. You might be able to with manifold casting hole being larger.  They only use rr cyl top and bottom holes on 390 GT pass side manifold.  GTE (I know) is a 14 bolt head. The N heads that were used on CJ and late 427 W codes were drilled for 16(CJ) and 14 bolt(427). I can't speak to any later serv heads. I can say that I have N heads and 390 GT Exh Manifold and the only place it ever leaked was on Pass Side rr port.

I am like you; not sure while they didn't just use CJ manifolds on all performance FE applications.

As far as the chamfer in the later 68 390 GT manifold for the exhaust donut used with no ctl valve/spacer and the different H-pipes that is in MPC. The casting number is same but the svc PN is updated for late 68's. Mt manifolds have a mid-March casting date. These manifolds seam to show up at different times in late 68. I was a little confused with mine so I did some research and the dates really get people going. Some say that casting number is not used with 68 manifolds with the chamfer but a number like me have it.

There are guys who have experience with this and know more then me, you might want to try posting on FE Forum.

Kyle, What is the date code on your pass side exhaust manifold? Mine is 8C14. If the casting date is prior to 2/11/68 (date from MPC) then some one machined chamfer.


Kyle

Hi thanks again for all the good information.

My RH exhaust manifold date code is 6J21.
Today I fixed it and it is like original.


gt350hr

Celebrating 46 years of drag racing 6S477 and no end in sight.


PrettyMuchAShelbyGuy

Not easy to weld cast iron.  Did you use nickel rods? stick/arc or?  Very nice!
Tom - DFW, Texas

Kyle

Quote from: PrettyMuchAShelbyGuy on November 01, 2021, 03:44:34 PM
Not easy to weld cast iron.  Did you use nickel rods? stick/arc or?  Very nice!


Thanks.
I used stainless steel welding rods to weld it.