Mk2 Cobra engine

[Dan Case]

The general question of whether or not a given 1963-64 five bolt High Performance 289 engine was an original engine for a new Cobra comes up several times a year.

#1 First, the math is not favorable for any loose engines being original to a new Cobra long ago.

1963½ model year High Performance 289 engines.
Approximate number manufactured = 1,550 each
Approximate number installed in new street Cobras = educated estimate about 88.
Chance than any 1963½ engine went into a new street Cobra = about 6%. Remember, some engines sent to Shelby's works were race prepared and went into Cobra racers and or any other car somebody bought a complete race engine from Shelby American for.

1964 Approximate number manufactured = about 5,300 to 5,400 each
Approximate number installed in new Cobras = educated estimate 400 plus.
Chance than any 1964 engine went into a new street Cobra = about 8%. See race engine note above.


#2 Second, if an unrestored intact engine does not exhibit all or at least most of the deletes and additions made specifically for new Cobra installations, chances are probably zero it was factory installed in a new Cobra. A really easy one to spot, new engines for new Cobras received an engine oil temperature measuring sensor in their oil pans.  Yes, oil pans can be swapped around but if the engine is completely intact as day one and is missing the sensor, it was not an engine prepared to go into a new Cobra.


#3 Third, people think Cobras and Fairlanes when they think five bolt High Performance 289 engines but that was not all. Several different performance and or racing cars in the USA and elsewhere used them. Example: Early Ford Advanced Vehicles GT40s used what started off a as five bolt High Performance 289 engines from Cleveland Ohio. Genie sports racers, Lotus 30 racers, very limited number of Mercury Comets, and others used these five bolt engines.  There was even a group of 1965 Mustangs completed with "1964" five bolt High Performance 289 engines before six bolt engine production started in July 1964.

[Dan Case]

Block date 3E10, Assy date 3E15A and Carb 3DC (still has original Autolite).

Is the carburetor a C3OF-AB assembly or C3OF-AJ assembly. The date 3DC falls in between the known dates of 3DA for C3OF-ABs and 3EB for C3OF-AJs.