CB750 engine numbers

[Bully40]

Hi all,

This is my first post so be gentle with me! I have recently bought a box of bits formerly known as a 1976 CB750F1. The engine that came with the bike was already stripped and is just the lower half so
I then bought a second engine for the cylinders etc.
The problem I have is that the first engine has a serial number I can't seem to find any information on, the number is B750GE 1004187, is this an engine number from a different model altogether?
it all looks identical to the second engine which is a CB750E-2560070. the first engine has the black finish which I believe should be the later run of these engines maybe?

Any info will be greatly appreciated.

[Bryanj]

The GE makes it a European model F2

[Bully40]

Thanks for the info, I was starting to wonder what the hell I had here, I think I will use that engine as the base and the "proper" one as a donor.

Cheers for now 😊