I have a 2001 GMC 2500HD 4x4 Extended Cab that I'm getting ready to sell. It's got a 6" Superlift suspension lift. Anyway, I'm going to sell it on Cars.com and maybe Trucktrader.com. I'm unsure whether my truck is a K2500HD or a C2500HD. I've got the original sticker right here with me and can't find it anywhere on there. Does anyone know how I can find out which mine is?