Keith, Yes, Pull the front end apart. It's not really that much work. Makes the engine in/out WAY easier. I left the trans in the truck on the last one.
I'll assume you have the correct rear lifting bracket. FYI, Reman engine may NOT have a fuel pump drive gear installed. Front cover will be fully installed, no gear ?????
Also, There may be 1 threaded bushing in the block for the ECM mounting, I've never been able to remove them. I'll get you a Cummins # if needed.
Snap-on now has some Voss Fitting fuel line removal sets, Some of those are a PITA in chassis. The tools help.