I decided it’s time to retire the 99 and get something newer, I found a really nice 2008 6.4 MT Lariat Crew cab with 45,000 miles on it.
It drives really nice and the power is unreal compared to my 7.3
What kind of things should I be checking for?

 

try to get ahold of an "oasis" report which will let you know any work that had previously been done to the truck...coolant level...if the truck has ever had the emissions altered (dpf deleted) if tip is really black is usually an obvious sign.. I'm sure more people will chime in 2 help also.. if taken care of there one of the best trucks you'll ever own... good luck!

 

maintance records...5K oil changes and around 10K fuel filter changes..coolant testing/maintance as well.

OEM filters only for fuel and oil.

Check the radiator seams..anything modern now has plastic tanks...they suck.

check the tail pipes..because of emissions now they should be fairly clean to a little grayish.

It would help if you have pics or a link to the truck.