3. the knob was for changing the timing based on the grade of fuel you were running. again the manual would explain this feature and the proper use of it. With todays gas you should not have to mess with it once you have the truck running good.
You have been mis-informed, FriedGreenTmater. The knob is on a grease cup. The cup is filled with grease and the knob is turned a dab every so often to lube the distributor shaft.
