I just bought a 1968 F100. The VIN is F10YR****** which when I decoded it says it originally had a 360 (if I got it right). But the guy I brought it from said it has a 390. I got C6AE-XXXX-G off the top of the engine. Which I was told means its a '66 engine. So I'm assuming it's a totally different engine. How do I tell what engine it is?

 

You both could be right. The VIN tells you what it was the day it left the factory, & no more. After 40 years many things could have been changed.

All the FE engines look the same on the outside, the 390 is a more engine so all FEs become 390s on sale day.

Top of engine = intake, if a 4 barrel carb has been added, a 4 barrel intake would be required.

C6 = 66, Bill can answer in full detail.




John

 

66 parts were placed on many vehicles after 66... You will need to check the stroke of the motor (or pull the cast number off the crank), search for the how-to. This will give you a better understanding of the internals of the motor, which is where the difference between 360 and 390 reside.
--Mike

 

F10 = F100 2WD

Y = 360 2V

R = San Jose CA Assembly Plant.

On sale day, 360 engines magically become 390's! Most sellers haven't a single clue, many have never heard of a 360, so on sale day...the 360 (or 1965/67 352) becomes a 390.

Your truck is 43 years old. So...who knows what changes could have been made by previous owners?

And, do not believe a single word a seller claims. Sellers (private or not) can lie just as well as new/used car dealers, lawyers and...politicians!

Research first, ask questions from knowledgeable peeps if unsure.

1968/76 360/390: The bore is the same (4.05"), the stroke is different: 360 = 3.50" / 390 = 3.78"

The fact that the intake manifold (top of the engine) has a C6AE-9425-G casting number marked on it, does not mean the engine is from a 1966.

If it's a 4V manifold (a popular swap), it's from a 1966/67 390/410/428 Passenger Car. F100/350's with FE (352/360/390) engines did not come w/a 4V until 1974/76, and then 390's only.