428 Cobra Jet question re Aluminum intake in STOCK

[DeuceCoupe]

We are looking at the 1968 428 Cobra Jet on a couple Ford forums.
Trying to figure out what intake manifold was legal & was run in STOCK class at its debut at Feb 68 Pomona.

The first 50 Mustangs with 428CJ were built with the aluminum 428 Police intake, because the cast iron C8OE-A intake wasn?t in volume production yet, though there were a (very) few around.

Our consensus is that the aluminum 428PI intake was legal on the 428CJ, at least for Feb 68 Pomona STOCK eg C/SA=9.00 class, and legal in STOCK for many years after that.
Sorta makes sense, because the first 50 cars left the assembly line that way on Dec 26-27, 1967.

But now, as of 2008 In the NHRA blueprint file, it says in STOCK, the 428CJ has to run the iron C8OE-A or C8OE-C intake. The aluminum 428PI intake C6AE-H is illegal in STOCK, and only legal in SUPERSTOCK.

Anybody know when and why the aluminum 428PI C6AE-H intake went from legal to illegal for the 1968 Model 428CJ cars in STOCK?


(From the NHRA Blueprint file: )
Issued: 1 July 1968
Revised: 6-21-76, 8-6-76, 6-23-94, 12-07-94, 6-24-95, 9-5-95, 1-1-96, 5-12-99, 8-22-02, 3-18-03
5-9-07 WR, 8-28-08 WR

and the intake note says

335 428 11.0 1-4 Holl C8OF-AA/SM,C8OF-AB/AUTO C8OE-A,C,Note 6 1.73 H 68.00 4,13
C8OF-AA (4174) C8OF-AB (4168)
6-C6AE-H is Alum manifold, may not be used in Stock, SS ONLY

[Mike Gray]

It may be a mistake, checking on classracerinfo.com I found the only restricted manifold was the -C cast iron
Intake. The intake manifolds vary depending on hp ratings and heads used.

Intake Manifolds: Casting No.
C6AE-H Aluminum
C7AE-F Aluminum
C8OE-A Cast Iron
C8OE-C Cast Iron May not be used in Stock, SS ONL

I looked at the NHRA blueprint file, note #6 is alternate intake and list the two aluminum intakes.
Where did you find the “may not be used in stock” note as I don’t see it?

[DeuceCoupe]

Originally Posted by Mike Gray

It may be a mistake, checking on classracerinfo.com I found the only restricted manifold was the -C cast iron
Intake. The intake manifolds vary depending on hp ratings and heads used.

Intake Manifolds: Casting No.
C6AE-H Aluminum
C7AE-F Aluminum
C8OE-A Cast Iron
C8OE-C Cast Iron May not be used in Stock, SS ONL

I looked at the NHRA blueprint file, note #6 is alternate intake and list the two aluminum intakes.
Where did you find the ?may not be used in stock? note as I don?t see it?

WELL the .DOC files all look different now vs the ones I downloaded circa Aug.2008. Thats where I got the language I copied to start this thread.

Now, in the .DOC files, all 4 intakes you listed are LEGAL in Stock, for all 3 years 1968-69-70.
The online detail also shows all 4 intakes legal for all engine combos & years ie
1968-69
428-A
428-B
428-C
428-D
1970
428
428#

Exception:
1968-428-335-B shows
C8OE-C Cast Iron May not be used in Stock, SS ONLY

No reason for the extra words to be there- of all intakes, C8OE-C should always be legal on any 428CJ (except maybe the 1st 50 cars built in Dec 1967 with C7AF-F) because after very early 68, every 428CJ came factory with C8OE-C iron.

So I think this part
1968-428-335-B shows
C8OE-C Cast Iron May not be used in Stock, SS ONLY

Is just an echo from the old files. Needs to be fixed in here:

http://classracerinfo.com/EngineSpec...3030&MAKE=Ford

OK so now, all the intakes are legal for all years.
Our guess on the Ford forums is that
C7AE-F
C8OE-A
C8OE-C
should all be legal for Model Year MY68 because cars left the factory that way, C7AE-F on the 1st 50 (Dec 1967) cars, then C8OE-A iron early on, then C8OE-C iron.
C6AE-H was not used in production, but is identical to C7AE-H except for the thermostat housing hole so makes sense to make that legal too.

For MY69-70, only C8OE-C iron was factory, but I guess the rules are getting more liberal now.

This clears up a lot thanks for reminding me to look anew at classracerinfo.com

[DeuceCoupe]

Continued:
In this sense, the old circa Aug.2008 Blueprint.DOC files were more accurate for MY69-70 428CJ:

They list ONLY the
C8OE-C
iron as stock, NO listing for C8OE-A ironor C6AE-H aluminum or any other intake for MY69-70.
That was accurate vs actual MY69-70 production.

The only (circa Aug.2008) .DOC file i had questioned was the MY68 file, which correctly listed C8OE-A and C8OE-C iron as legal, but then had C6AE-H as not stock legal.

In fact, even that file was missing the C7AE-F aluminum which was factory on the 1st 50 cars built in Dec 1967, though C7AE-F is functionally identical powerwise to C6AE-H.
Wow a lot of typing.

[Adger Smith]

Always check in: https://www.nhraracer.com/content/ge...634&zoneid=132
That is what NHRA Tech goes by not ClassRacer