Some of the restore pics of the 601's that are on this site the machines have a different type rear end as the one mine has.My machine has the 2 drive shafts running back.Did these machines come original with the single drive shaft and different type rear end?What would the difference be in steering them and what would be the better way to go.I would like to put an auto trans in mine and I dont think I can with the set up I have.What would it be worth to switch over to the single drive shaft and different rear end?What would be envolved in swaping it over?