It depends on the engine that is in the truck.
For a small bore engine 9.0L and below 5000 miles
large bore 10.0L and above 8-10,000. We have some driver's that go 12,000.
The reason for the lower mileage for the small bores is they are in a lot of stop and go traffic and they may use a HUEI injection system.
What is includes parts wise is oil, oil filter, fuel filters, and a oil and coolant analysis kit.
then make up a check list of stuff you check:
3) trans fluid
4) grease the chassis (depending on the truck could have up to 50 grease fittings)
5) power steering fluid
7) belts and hoses
8 ) brakes (visual inspection)
9) rear ends fluids
10) wiper solvent
11) air filter minder
12) parking brake
13) front suspension
14) rear suspension
15) steering linkage
16) drive line
17) instrument lights
18 ) fuel lines and tanks for leaks
Then have a spot for a general condition of the truck
On top of the form have stuff like:
3) engine manufacture
4) engine ID number (like with a CAT C15 the engine number could be MXS98765)
4) unit number
does this help? Or would you like me to make it up in an excel format? I am geeky like that.