1972 dart - stopped running while at 50 mph ? no warning

points checked ( post #55 ) and are fine . engine still in time and not jumped , as below

with good coil hotwired , and swapped out condenser with and old one still did not start . dwell then checked and reset to its happy place at 34 . no start . rechecked spark with tester . sparking good from coil , kinda weak at spark plug wire . then i pulled out of the trunk an old , kinda funky rotor with bent up tab and all . however , i noticed it looked slightly bigger than the 3 months old one that was in the car . i mocked up with an old cap that came off the car from the last tune up and the new rotor could barely reach the contacts ( not exact science here , just holding it in the cap loose ) but then checked the old rotor and it was way close up to the contacts . anyway , put old funky rotor in and it started right up with the number 1 spark wire still attached to the spark tester ( I.E. ran on 7 cylinders ) . i shut it down then . connected the coil positive wires , the number one spark plug wire , and the air cleaner etc . started up great and ran for a half a minute , before i cut it off because i heard what i think is a valve tap . i guess its possible the rotor i recently got was wrong and was just long enough to last a few months , or it failed or something made it fail .

my question now is the valve tap , now i know its been sitting for a week being cranked , so i get there might not be much oil in there up top . plus its really cold out . was only running one minute . the points adjustment should now have changed the timing a little . timing showed just a hair or two after 0 . cold engine at idle ( not fast idle ) . i think i usually have it at 2.5 ( with engine hot ) , but cannot remember if that was before or after 0 . i wrote it down somewhere , but finding that will take another week . the plan now is to get a new rotor ( or two ) , and while at it a condenser , another coil , cap wires points , just to have extras . then with a new rotor etc . warm it up and set the timing . that might take care of the valve tap , but how concerned should i be running it like that for timing it etc ? its not a horrible tap , but i know its not good to hear it at all . i think its just one cylinder , but will check all by the hose/ear method if it doesn't go away quickly after warmup/timing . any suggestions before or after setting the timing ? thanks again everyone . i appreciate everything .
I see nothing about where you verified timing is right. Can you elaborate? Just because the points are "good" means nothing.....except the points are good.