Picked up a snow thrower for my sears tractor got most of the parts except the part that attaches under mower. The steal plate with the pulleys on it. Need the name of that part and part number if available. Also does anyone know if the above thrower will fit my tractor model # 917.271821. I know there r only a few different set ups but every time i think I'm close to getting info I hit a wall. So I figured I ask the experts. Thanx in advance for any help/info you can give me.