My good friend has a 2000 C4500 cab-over box truck that he uses for his tiling business. The truck has the 6.5L Turbo Diesel according to him. His transmission went out this week so he's need of a rebuilt or used trans. First of all, can anyone tell me the exact transmission he would have? Next, where is a good place to find a new, rebuilt, or used transmission? He wants to get the truck going again for as cheap as possible, just like everyone. The auto service center he took the truck told him $4,000 for the rebuilt transmission and then another $500 for labor. Can anyone point me in the right direction so I can help my buddy find a better deal?! Thanks in advance!