Engine ID help please

[John Wurner]

This engine without numbers is installed in my D which also came with the original engine.
Any ideas what this is?
Thanks.
I have a number of pics but dont know how many I can attach here.

[C J Murray]

John- where the front center of the shroud meets the case...look at the boss for the through bolt holding the case together. There should be a production number on one side and an engine type(616/?) on the other side of the case joint. If it is a factory replacement case there may not be an engine type. The production number can be converted to a date with the Pellow charts. You never know what is inside but it is made to look like a S90/SC with an old fuel pump and early fan shroud.

[John Wurner]

Thanks, CJ, those are the missing numbers, there is no 616/... and no numbers on the third piece. Engine runs very strong, is there a way to tell by the compression?
John