I am looking at a 2003 cummins. 151,000 miles I have heard alot about valve seats dropping and have seen a 04.5 drop one on a dyno and make a mess out of things. My question is how common is it and should i look at a newer truck because of it?

 

it will happen due to a lot of egt temps not all of them will do it depends on how much mods were done. have an 07 that dropped them so no year is imune to it