question regarding 427 serial number

One of the big blocks I have is a 1969 model year 435 horse 427. It is
not an engine with matching dates, but the block is a 4 bolt with:
3955270 casting date I 6 8 ( Nov 6, 1968 )

I found this information 3955270 427 69 335-435HP 4-Bolt

But the serial number is
serial number CCE 952320

I have never been able to find out what vehicle used that code. One of the possibilities, is that it is a COPO engine, or a warranty replacement engine. Can anyone help me identify the engine? The engine has a happy home, but I would like to know what vehicle it came from.

The crank I have is not reground, but is forged,cross drilled, and grooved. I was not
aware that Chev grooved the big block cranks.

Are the closed chamber square port heads of any value to collectors?
Could I get away with running the 12.5:1 pistons with 300cc aluminum heads on the street?

I was going to use the Chevy intake manifold ( casting number 3933163 ),on one of my 454s, is it too valuable to be doing this?

I have looked in a lot of places and have not been able to get any answers.
Bob