SOHC Intake Manifolds

[jayb]

Hmmm, took another look at that picture and it does look like the headers on that engine could have been modified 63-64 427 cast iron headers.  The flange is definitely steel and has been welded to, but Ford may have hacked off the FE wedge flange from a set of the cast iron headers, cut a different angle on the tubes, and welded on the steel flange.  Never noticed that before...

[Autoholic]

Here is a PDF of that article from HR. You should be able to download a copy in the upper right.

https://drive.google.com/file/d/1XnaSK1KeiNPgaosDDv1xhQSBBdGG4sGP/view

[WerbyFord]

Here is a PDF of that article from HR. You should be able to download a copy in the upper right.

https://drive.google.com/file/d/1XnaSK1KeiNPgaosDDv1xhQSBBdGG4sGP/view

Awesome! I didnt have thi article.
Looks like the 8v didnt exist yet, and the 4v just says "over 600hp" which jives with the later 616hp rating.
Doesnt say if that was in A-Curve condition though (steel headers and blueprint).

Recall from Jay's testing, on a good old 427 circa 400-450hp, the long iron is about as good as steel headers.
But at 600+ hp that changes, so the configuration still matters for that 616hp and 657hp rating.