How do you tell a 534 from a 477 without pulling them down? Bought several nice running 3-axle U850 ,40,000 gvw. The engines have been R&R'd in each one several times. After steam cleaning, I didn't find any ID such as distributor tags. Thanks for your help!

 

All I can find here is bore and stroke on a 534 being 4.50 x 4.20.

Scroll down to "vital statistics". One entry in here talks about what size truck got what motor. Yours should be 534s as those sound like fairly large trucks.

 

The 534 stroke was 4.20, the 477 was 3.75. Pull a spark plug, and stick in a very long bladed screwdiver. Carefully rotate the engine, marking top center & bottom center on the screwdriver shaft. Might not be precise, but close enough to tell if it is a 534.
Godd luck.