What are the best ways to tell Mopar 383, 400, and 440 apart?

Aside from the casting numbers, what is the best way to tell these three engines apart?|||welllllllllllllllllllll i always looked on the valve cover and i owned them new|||The 440 will have a machined 2x3 inch pad with 440 and other info stamped, and it will be just to the right of distrib if looking at engine in car. The 383 and 400 don't have the pad.