Just as with any reliable motor, the problem comes in with high mileage accessories.
Replaced 200k alternator only to have the 203k vacuum pump let go and take out the belt (it seized the pully and the belt heated up and popped) about 250 miles from home. My 4 door 8' bed truck with the new to me Uly in the back looked ridiculous up on a 26' flatbed. I think our total height was about 12'3"
The crank may spin forever, but be proactive on replacing the accessories bolted to the outside.