428 purchased from ford in 70's

I have a interesting one. I have done tons of reading but the opinions vary greatly. Anyone that can help please feel free.
A friend of mine bought a 428 from ford in the early 70's. He still has the recept showing 428. He put it in his truck and ran it until last year. He then removed it and sold it. The motor was never
rebuilt. He recently sold the motor. The guy that bought it (2 months ago) just contacted him and is not very happy. He claims the motor is a 390 at 40 over.

Here is the numbers we saw on the motor before he sold it.
c6ae on the connecting rod bearing caps
UA on the crank ( the new owner says he sees a 2 in front.)
c8ae-h on the heads
2e31 oil filter housing area
352A back of motor
53 back of motor
252618 back of motor

This was bought as a 428 from ford ..... can anyone help???
What is up with this ?? Thanks for any information !!

I agree with Bill it's a 390. Measure the bore first of all to be sure. 4.13 std +.040 would be 4.17 on a 428. A 390 is a 4.05 std +.040 and 4.09. The 2UA is a 73-76 390 truck crank with a 3.78 stroke. 2E31 is the date code of 72/May/31. If this was bought in the early 70's as a 428 it would have been possibly a service replacement engine as the 428 by then was no longer available in production. I know Ford had a reman plant in Fairlawn NJ where they did most of the rebuilds on the reman engines. I've got the wrong engine both times I ordered a reman from them at Ford. First was what was to be a 390 and turned out to be a 429. Second a 428 that was delivered as a 390. So it's very possible they mixed up even if a new shortblock was ordered. The 53 is the mold number and the partial vin must be the 252618 which should not be on a service replacement block which tells me it's a rebuilt. Unless it's some sort of product number used at the reman plants. There should be another letter after the C6AE on the rods. Look for C6AE-D which are the good 428 rods. These I've found in 390's before a few times and was not uncommon. Sounds like your bud was burned on this way back when. Maybe the engine was tagged wrong and they all look the same on the outside so anything is possible. Bummer, G.