The chassis, hood, cab, etc, are very similar to my orange 389 daycab.
I use this truck to pull my matching white fuel tanker http://rebrickable.com/mocs/MOC-7501/motomatt/117-fuel-trailer-for-semi-truck/
These types of files are created with the LDraw system of software. You will need to install compatible software to open and view the instructions.
A full list of available software is on the LDraw site.
This MOC also has a LEGO Digital Designer file available: 3D Model