I did a search here for this site, but nothing came up so I figured I would post it. Sorry if this is a duplicate.
I came across this cummins site while digging for information on my engine. https://quickserve.cummins.com/info/index.html
It allows you to create a free account and enter up to 5 cummins ESNs (engine serial numbers). Once you enter your serial and some other information it looks up your engine and gives you access to the owners, maintenance, and service manuals for your specific engine. It also has a parts lookup section that I haven't dug through yet. There's a ton of great info here.