I have a good engine recovered from a dragline that I junked. Would 9S 8073 work in a D2 Cat???

The Cat SNID book lists 3 of the 9S engines and they are 9S00001 & up a D311 marine engine and a a 9S04001 as a D3400 an industrial engine and a 9S05001 as a D315 engine.Does your engine have the big fuel injectors in the head that stand up in the air or are they all down in the head and the lines screwed on them there? If they are the injectors that are the large ones sticking above the head then it would be the D3400 engine.What SN D2 do you have? There would have to be some swapping around if you wanted to put the D3400 in the D2.

They are the small injectors.

By the serial you gave then if things are right then the shovel engine is a D315 and the D2 would be a D311 if it has the smaller fuel nozzles in it. No the D2 engine is smaller than the D315 so they wouldn,t fit but do look similar. The D315 is a 4 1/2" bore and if the D2 has the small nozzles too it would be a D311 with a 4" bore. What is your D2 serial number as the 4" bore engine would be in a 4U narrow gauge or a wide gauge 5u.

I would think it was unlikely that any dragline had a D311, but maybe a D315 in the smaller machines.

What dragline was it taken from?

I show the 9S8073 as a 1951 model D315.
No go on the D2.