Sometimes the oil pump drive extension has some wear to the plastic joint coupler if so the shaft can lean far enough of center to hit the bottom of the nose edge ,you would know this though probably. Anyways Look down the length of the shaft hole see anything with an led flashlight like the slotted end of the shaft beside the gear ? What position is the slot in ? Ok take the distributor hold it in the right position to put it in toward the front with rotar or one tooth to the left or center front: what is the pins position on the bottom of the gear is it 1 o'clock? 2 o'clock ect. decide then take a long screw driver and turn the oil pump drive shaft untill the slots the same position as the position of the pin in the gear at normal install position .remember the gear will turn to the right at least 1/8 a turn when dropping into meshing spot". It's normal to possibly move the drive shaft like a 32nd of an inch to finalize the mesh of the drive pin or rock the crank back and forth with say a large rachett and socket untill the gear it finds the shaft slot in the hole" of course then and there get back( turn) to the zero on TDC firing stroke ( preferably by hand)and see that your rotors left of center ( 1/8th clkwise or about 35degrees left of dead ahead) .when on TDC from there you can put cap on and turn key to on then watch for spark turn * rock the distributor untill it first a sparks out the wire or terminal ( no 1)thats the basic timing ,it will run there but generally add 10 degrees( from first spark position) if your shure your on TDC you can't go wrong...I'm saying use your wrench to position the gears as turning it over it might skip a teeth or two unless you stick the bolt and clamp on ( ride up) don't turn a motor with a wrench while keys on...just move the distributor if your checking for initial location of the distributor body and the rotor to terminal spot."(spark) Hope this isn't to confusing...I forget but maybe the pin in dizzy nose is aligned with the rotor direction..
