Sometimes you are better off leaving well enough alone, sometimes it makes sense to tackle a project while its out of the car.
Something I would suggest is remove the water pumps, send them out to Skip's for rebuild, and while they are off you can clean clud out of the cooling passages. Easier to do now than later when is in the truck. You probably already know there is a bolt inside the lower hose outlet that can be a b*tch to get to. Maybe replace it with a stainless steel bolt and ani-seize for future maintenance.
Congrats on your new powerplant, glad to hear you are pleased with it!