Can someone tell me what part number and where I can get a replacement inducer motor on a Rheem Criterion, circa 1992, model RGDG-150ARJR? Already had someone come out and said ball bearings were going bad and motor should be replaced. They wanted to charge me $400 for the motor alone. I see motors on the internet for about $150-$250. I just don't know which one to order. Grainger is in my area and they don't sell Rheem furnace parts.