I have a craftsman model 917.253741 mower and need a drive belt to run the mower deck, which is a 44" deck with 3 blades. Can anyone help?

Hi,
The parts breakdown is at Sears' site, but the deck is a separate item for that garden tractor. It should use two belts; 131264 is the primary hooking to the engine and 131290 is the secondary going blade to blade.
Peace,
Clarke

Hi,
May have found a manual close to yours. Check:
List of Craftsman Tractors-Riding-Lawnmowers
Peace,
Clarke