I have a 460 i recently picked up, i noticed pulling a load up a hill, or any heavy load for that matter, i kind of run out of power when i dont think it should. At the start of a hill it will start grunting louder and start in with some light black smoke as a diesel should then as the rpm drops a little off 1800 or so it stops smoking and starts slowing down until i kick the ta in, once i get to the top and the rpms start to climb then it will smoke again, i may be wrong but shouldnt it smoke more when it really starts to work rather than clear up and fall on its face, any other diesel ive ran you can run them down until its a big black cloud and they keep chugging. Does the fuel maybe need turned up or timing adjusted better, i just had the pump completely rebuilt.