I've had the 66 inch since they first came out. The belt I had a tough time replacing at first was the drive belt. Wasnt enough clearance for the belt to go
under the engine shaft. Trick is to loosen the 2 bolts on the plate the engine sits on, and pry the plate up a tad. The bolt holes are elongated for this. I use swisher belts, haven't found 133 in belts anywhere else.
lar