I need the blade belt for a Murray 17hp twin(42A707) 42 inch cut "Widebody". The old one stretched and broke and I cannot read any numbers on it. Can somebody help me and give me the right part number?

Use the dom and model # from your unit and carry them to a small engine shop and get the correct belt. There are two different belts for the 42" cut, it will depend on the year model, that is why you need the dom code.