Simple Engine Identification

[75DBE]

Somewhere in the middle of turning wrenches yesterday with crazy man Frank -- who somehow convinced me to take out my frozen engine at 5pm on Sunday -- he tried to educate me on engine identification. Needless to say, it didn't stick. I'm hoping that the engine we just took out of the 75DBE is the original engine -- can someone confirm for me? The code on the block reads -- D4DE6015 - GA4116 (pretty sure on those last four ditgits). If it is not the engine that originally came with the truck, then I have some decisions to make re. rebuild or crate motor. Thanks all!

[akaFrankCastle]

Somewhere in the middle of turning wrenches yesterday with crazy man Frank -- who somehow convinced me to take out my frozen engine at 5pm on Sunday -- he tried to educate me on engine identification. Needless to say, it didn't stick. I'm hoping that the engine we just took out of the 75DBE is the original engine -- can someone confirm for me? The code on the block reads -- D4DE6015 - GA4116 (pretty sure on those last four ditgits). If it is not the engine that originally came with the truck, then I have some decisions to make re. rebuild or crate motor. Thanks all!

John, here's a handy link to help with that casting number: http://mustangtek.com/FordDecode.html

Now, GM did stamp the VIN number of the associated vehicle in to the block to identify the motor to the vehicle it was shipped with. Ford, however, did not. The number you will find stamped in to the rear of the block on the flat spot behind the intake manifold simply indicates the year, plant, and production number of the motor. As such, there is never really such a thing as a "numbers matching" Ford vehicle. There is period correct though. Period correct would be a vehicle that had a motor that was manufactured in a time line that was complimentary to the production of the vehicle.

If I recall correctly, the number on the motor we pulled from your truck was "D4DE-6015-AGA" and below that was "4I16".

It would decode as such:
D: 1970's era
4: 1974
D: Application. According to the link I posted above would indicate a Falcon/Maverick intended motor.
E: Engine
6015: Generic Ford part number category for motor
AGA: Revision

4: Year (1974)
I: Month of the year (I is the 9th letter of the alphabet. September is the 9th month of the year)
16: Day of the month
16 September, 1974 was the date the block was cast.

One final number you can look for is stamped on the upper most ear of the water pump mount/timing chain housing. See picture below. Fuel pump is in the lower left corner for reference.


The number in the photo is "1B19E". This is the assembly date, meaning the date the motor was assemble and first test started.
1: Year (1971 in this case)
B: Month (B is the second letter of the alphabet. February is the second month.)
19: Day of the month
E: Assigned designation of the inspector test starting the motor.
19 February, 1971 was the day this motor was assembled and started.

Using these numbers, check your sticker in your door jamb to see what the assembly month and year are. If they fall after September 1974 AND after the number stamped near the water pump, your motor is "period correct" to the Bronco. I would ignore the "D" indicating Falcon/Maverick application. Ford was, in 1975, scaling back production of the Maverick (the Falcon line ended in 1970) in preparation for the release of the Granada and Mercury Monarch. Chances are the motor was part of an earlier order that was later not required and then shipped over to the Bronco production lines.