How can you tell if you have a 105 or 130 amp alternator in a 2001 Silverado LS 4x4 with a 4.8? I am wanting to change my serpentine belt, but there are seperate belts for the 105 and 130 amp alternators. Are they the same, with the 130 amp belt being more heavy duty? Any help would be greatly appreciated. I am so confused.