[PaulProe]

I am looking at a FE block and a little uncertain on the identification of it.

The date code indicates it is a Jan, 1965 block.

The casting number is C5AE-A

Going to fordifiction.com and their chart of casting numbers, it appears the block could be one of three:
390 or 330HD or 427 top oiler

The block has a flex-plate still bolted to the crank which indicates an automatic transmission. With that in mind, I would rule out the 330 since that was a HD truck motor - unlikely it was an automatic

Is there a way to tell if it is a 390 or 427 without pulling a head or pan or trying to second guess the stroke thru a sparkplug hole?

Are there other numbers that I should be looking for?

Thanks

Paul