hoses
I replaced all of the rubber hoses on the cooling system on my '97. EVERY one just because the rig was going on six years old.
I found out that the 90* elbows are very expensive. If I remember right, they are 5/8" ID. I noted that if I were to do it again, I'd find some "will fit" heater hose from some other app and cut 'em to size rather than buy the pricey MOPAR pieces.
I believe that there were 4 90's and then there were 4 or 5 short 5/8" straight pieces connecting other lines together such as the transmission cooler (autos) on the pax side of the block. And naturally there are two longer 5/8" pieces going to the firewall.
The 1/4" "U" shaped bypass hose on the thermostat up top is another pricey item as well.
I bought mine at the dealer. I might have been able to get them from Cummins, but I don't have a local Cummins dealer. A reliable one anyway.
You'll have fun contorting yourself in the engine compartment should you decide to replace all of the hoses. They put them in the darndest places. It can be done though.
I did mine in conjunction with a KDP tabbing. That got the radiator hoses out of the way while doing that job.
Some of these hoses may be 3/4" rather than 5/8". I am working from memory and it ain't what it used to be.
Good luck,
Tim