Bought a used GR2707 snow blower for my GR2120, came with most of the parts except for the rotation handle parts, loaded those into cart and realized also need a hose to go with it but per parts diagram there are TWO hoses? So apologies in advance, but why are there two hoses? Also I am planning on ordering a manual, but if anyone has one I would greatly appreciate, live in Minnesota and snow season is here so I need to get this stuff ordered and on. Blower also shows the gearbox need 80w90 agma5ep oil.....can't find the agma5ep, from what I can see equivalent is ISO220 like they use with drilling rigs?