Decoding Intake Casting Numbers

[ChevyToughRebel]

I recently acquired a 4bbl intake manifold and am trying to figure out exactly what it is. I found that 289 and 302 intakes are the same, but I want to know if it was originally a 289 intake or 302. There is a 289 stamp on the underside of the intake which gives me a hunch that its from a 289? Is this a reliable guess?

The important numbers off the intake are C60E-9425-B which from my gathering means 1966 Fairlane, Engine, Intake Manifold, Second Design.
Date code number reads 5K28 which is supposed to mean 1965 October 28. Is this right because it does not match the decade year from the number above. Perhaps they dont match exactly cause the date code shows it was near the end of the year? Also if I was to sell this would it be considered a 1966 or 1965 intake?

Any help is appreciated, thanks!

~ Shane

[bjde0b]

I posted this before, but this should help you out.

This was a good resource for reading date codes:

http://www.classicmustang.com/decoding_part_numbers.htm

[FORDification]

There's actually a more-detailed 5-page tutorial on decoding those numbers right here on this site:

How to Decipher FoMoCo Part Numbers tutorial series
- Overview (Prefix, Basic Part Number, Suffix)
- Basic Part Numbers - Regular Parts (Chassis, Engine, Electrical)
- Basic Part Numbers - Ford Truck Basic Body Parts (Exterior and Trim)
- Hardware (fasteners, clamps, grommets, etc.)
- Ford Special Service Tools

...and another page on decoding date codes:

Deciphering Ford Date Codes

But to answer your question, it's a 289 manifold. The changeover to the "C6" castings for the 289 2V and 4V intake manifolds happened around May/June of '65. Aside from the casting date, there is some subtle machining around the back of the manifold to mount the backfire suppression valve (part of the smog control system) that is seen on the '66 engines that isn't used on the late, non-smog '65's. The late 1965 "C6OE" manifolds are painted black, and the '66 version is painted blue.