Well.........
I had a D200, with a 318, that had 112,000 when I bought it, I put another 60,000 miles on it, untill the smoke got too bad. Crank didn't need to be turned either. The reason for the smoke was bad valve guides and seals. LOL
(Someone had put a non plastic chain in it before I had got the truck.)
Lot of it depends on if the motor is overheated, ran hard, oil changes.......warm up habits................
My grampa had a 318 "A" fury, he logged 300,000 plus, with a couple timing chians and valve jobs.