GMC option codes
 

Early last year I purchased a 2001 GMC one ton dually with a Duramax diesel and Allison transmission. For the heck of it last night I checked the option codes in the glove box. Found out it has a 3.73 rear gear ratio with posi traction. Also found out it has code HVY which means a 2 " body lift, I thought she stood pretty tall. Has a 105 amp alternator with all the heavy duty wiring and factory hitch. Didn't find any surprises except no code telling how large a fuel tank it has ? Does anyone know what the standard fuel tank size was for a 2001 one ton diesel ? I'm guessing if it had a larger than normal factory tank it would have a code. I'm guessing it's around a 30 gallon.