i was recently speaking with another driver about my truck..i have a 2000 freightliner 660k miles(detroit 60 series) and about the past year i noticed it just doesnt pull the same like it use to...... he has a truck with over 1million miles and recommended i get an --i believe he said an "overhead"? what exactly does this do and whats the cost? he also said it costs about 400$...... its nothing wrong with engine, i just had cam replaced and some other work done on it, and never have had a major problem out of engine.... thanks
and for arguments sake-- i do have PM's done every 12k miles, among other things, so i do take care of truck
any info will be greatly appreciated