Ok so I did a little research and was curious since the windsor plant did not begin production until mid 66 (C6AE-6015-C) it would be very well possible to have a 66 coupe with what i thought was a 65 289 (C5AE-6015-E), but could actually have been the stock engine correct? Not sure if what I said even just made sense to me, do I need to elaborate more?

 

haha ok no replies maybe i need to reword that to make more sense.

 

what i am asking is it possible for a 66 289 to have the casting number C5AE-6015-E?

 

yes, anything made from 65 until whenever they revised the casting and gave it a new number will be a C5. they dont change the number every year.

 

It will depend on the build date of your 66. Decode it and find out when the car was built. Ford never threw anything away, so if yours is an early 66 it could very well have a left over 65 casting numbered engine. Hey, a 289 is a 289. One little number isn't going to change anything, and since we aren't numbers matching anyway, who cares?

 

car was born early july of 66 you are right a 289 is a 289 was just curious if it was possible im still running the same 40 year old engine she came with

 

Strange that you would have a 65 engine in a July of 66 built 66 car. I'm thinking you don't have the original engine because the 65 casting numbered engines would logically have been used up before January of 1966. You will never know the answer though. If it's a 65 289 it is no different than a 66 289, but you just don't have the original engine. It makes you wonder what happened to the original, doesn't it?

 

sure would like to know where her original 289 traveled off too, but im quite satisfied with the 65 289 shes got.

 

Three of the four Mustangs I've ownedrecently had the original engine when I bought them. I had to replace one however. The C6AE-6015-C was use into the 68 model year. It's the date code that matters.
Jim