Ford Lehman I-6 Identification

[Rotten Ricky]

Calling Ford Lehman detectives!
I would appreciate help in identifying a Ford Lehman I-6 marine diesel engine. I have a feeling that this engine has parts on it that are not true to the original model as they seem to contradict each other.

The cast ID just fwd of the starter motor gives the following clear alpha/numbers:
PB
7J27

703F.6015.BA (could be "8015" - the casting is clear but the shape of the 6 or 8 number is peculiar.)
On the aft-facing, low-positioned, simple plate covering the gears or whatever on the fwd stbd corner of the block are the clear alpha/numbers:

Ford
DD
2700E
2893B
On the sheet-metal valve cover just barely visible:
703-F-8562-BAA (it could instead be "8982" and "CAA") Note that it does not match the engine block cast numbers.

The Block would seem to be the most definite of ID but I cannot find this model in my internet search, especially the "703F" and the "BA" designation. I wonder if the valve cover and the other plate could have come from a different type of engine. In spite of what I am told there are no other ID plates on this engine.

The exhaust appears to be about 2.5" diameter. I am thinking that this is a late 1960's, 363 cu. in., 100 Hp engine. A 3" exhaust would probably have made the engine a 120 Hp model, though this might be another mis-matched part.

I apologize if this request has been covered by a previous thread but I could not find anything on the forum, probably due to my ineptness.

Thanks for any help. RR.