I worked for a taxi company, & it was not unusual to get 1/2 million kilometres out of a Ford 250. At the most a leaking head gasket on the alloy heads needed replacing.
Also the Bedford trucks that run stove bolt engines have a reputation for going forever.
I doubt they would be popular if they could not get 1/2 million k's My own Bedford has a Chev 292cu inch & this is still going after 40years! only problem was a burnt intake valve.
