For you 289 guys....

[LMH]

Originally Posted by Dan Case

15 each Cobras were finished new with 1965 model specification Fairlane six bolt High Performance 289s assembled specifically for use with automatic transmissions. Those 15 Cobras were the production run of automatic transmission cars. The engines and special High Performance C4 transmissions went together. It's all in the Registy. (Not to be confused with CSX2435 which was the prototype for both automatic transmission and factory air conditioning. We do not know if that car got a five or six bolt engine at the current time. Automatic transmission fitted production Cobras went ahead while the factory air conditioning idea died. ) Ford stopped assigning serial numbers to HP289 engines as 1964 model year HP289 engine ended circa late June 1964. Shelby American gave these engines identification numbers.

It is known for sure that 42 new Cobras were finished with odd ball five bolt engines assembled after the start of six bolt engine production. Ford did not serial number them but Shelby American gave them individual numbers. These engines contained both 1964 and 1965 model year parts. This is not in the Registry. I didn’t know it myself until we bought a car with one of these engines and I started researching them.

Five bolt 221/260/289 engines were made for 1962-64 model years. Six bolt 289 engines were made for the 1965-67 model years. All Cobras except those 15 with automatic transmissions had 1962-64 model year engines (XHP-260 and HP260 made during 1962, 1963 model year HP289s, 1964 model year HP289s, and the odd 42 engines tagged as being 1964 model year engines but containing some 1965 model year parts).

That’s the short version. My decades in collecting research notes on “Cobra engines” is currently 76 pages long.

Sorry... yes, 15! That's what I get for not looking at my notes and posting when I'm at work!
Larry