I have a 1976 murray riding mower model # 6-36508C where can I find a belt diagram for the mower deck?

Walk-Behind Mowers - Riding Mowers - Tractors - Cultivators - Snowthrowers | Murray (http://www.murray.com/manuals/) but I do not know if their records go back that far. Most deck belt diagrams have not changed in decades so a newer model may still help you. There are pulleys for each blade and at least two more. There is a spring loaded pulley on a swing arm and also the mandrel from the engine. Here is a basic diagram, generic, with three extra pulleys. http://www.weekendfreedommachines.com/discus/messages/60944/172491.jpg