The evaporator in the '03 Silverado is under the dash on the passenger side. Unfortunately to replace it, you have to remove the front dash. This is probably one where you will need to take it into the shop.
The front track of the 2003 Chevrolet Silverado-1500 is 5 ft. 5 in. (65 in.).
The front track of the 2003 Chevrolet Silverado-2500HD is 5 ft. 8.6 in. (68.6 in.).
No everything about it is different.
only when it stops working.
The most common cause of that is the front brake rotors are out of round / warped. Replace rotors are have them turned.
Replace shoes brake 2003 Chevy
you can't replace just the front wheel bearings, they are sealed so you have to replace the entire hub assemble and it will cost approximately $130 each side.
The 2003 Chevrolet Silverado-2500HD is 6 ft. 7.7 in. (79.7 in.)12V front power outlet(s) wide.
The 2003 Chevrolet Silverado-1500 is 6 ft. 6.5 in. (78.5 in.)12V front power outlet(s) wide.
look in the manual
buy a knew one and take it to a shop and let them do it.
The 2003 Chevrolet Silverado-1500 has rear wheel drive.