My dads got a 04' cummins and i'm not very familiar with the common rails. Does the fuel pressure need to be monitored on these trucks like i do on my 01'? Do they have a better setup than the VP44 trucks, in tank pump?

 

yes if you start hopping it but stock no

 

It's always a good idea to monitor fuel pressure. Both low side and rail presure on the commonrails. Rail pressure can be an invaluable diagnostic tool when they start running weird.