Rebuilt 4BT's
I hate to pass along "here say" but I spoke to Bob at Bob's Neosho Truck Parts in Wisconsin (supplier of our 4BT motor mounts) and in the conversation in response to me asking where all the mounts came from, he told me some things.
The group he sold them to sold them to a Cummins for remanufacturing. They sat on the blocks for a long time. Supposedly, again according to Bob, Cummins set a number of threshold measurements for how far an engine needed to be gone through to be called remanufactured. In other words, not all engines received new sleeves, pistons, rings, oil pumps, water pumps, you name it. They were test run and then items that did not meet specifications were dealt with, those items that met spec were not.
I have no way of knowing this to be true but it does affect my desire to buy any Cummins equipment that has a RX in the model number.