440 engine decoding help please

There are 2 440 engines which I am considering. Before I go check them out, I'd like to know what I'm looking at. The info on the first pad is:

T 440 E
6 19

The second pad is reported as:

8 440 EHP
1 51

What are these engines? Assuming everything else is equal between the two, is one more desirable for rebuilding than the other? Any help would be greatly appreciated. Thanks in advance.