Btwn 1996 and 2014, the worst motors ever made were in use. Electrical issues plagued Ford's triton V8's and head gasket issues were found on ALL ford explorers and the sport trac (explorer with truck bed). Head gaskets also very easily blew up on the Ford 6.0 powerstroke, and the 6.4 had the worst fuel mileage since the 460 C.I. gasoline V8. The only motors that didnt have issues for 20 years were the Triton V10, 6.7, and 7.3 powerstroke engines. The 7.3 was made mostly by International, but labeled as a ford, making it a slow, loud, heavy, and quite stinky motor. Now the 7.3 will outlast LB7/LBZ and 12 valve cummins engines, but LB7/LBZ and the 12 valve have much more power.
If i recommended any diesel engine from any manufacturer, here are my 2 recommends
Toyota HiLux diesel (can survive a f**king tornado no matter the year)
All pre 2020 Chevy trucks (favorite is the 1000 LB/FT 2019)