[Kevin in NJ]

If you really want to be sure you need to pay attention as you assemble the dist.

You need to be sure the main shaft is tight with no side play. The cam you use must fit tight and give even lift on each lobe when installed. Some repros fit loose and will not go on centered, or so I have read since I have only used originals. The upper plate must have a snug fit to the center of the dist housing. Again, if the upper plate does not stay centered to the cam you will get inconsistent gap. The fix is careful use of the ball end of a ball peen hammer to make the upper plate center hole get a bit smaller.
You also want to get some high strand count silicon insulated wire used for RC cars and airplanes to connect the two plates. See Vince Falter's website.

Remember that original parts properly restored are likely to never need to be touched again. Repro stuff can give you some interesting problems. Most people do not like interesting problems 20 miles from home. One major exception, the modern burn out proof condenser is essential.

The dist cam must be very smooth. Some guys have lightly buffed the surface to ensure smoothness. There are two types of cams. The original A cam and the B cam. The B cam gives a longer dwell (hotter spark) and was the only replacement available after the A production from Ford.

Do not forget to lube the cam with cam lube or Vaseline. Keep in mind the wear block on the points will wear faster until it matches the cam. The points need to be parallel and inline. Points need to be replaced when the wear block is really worn out unless there is something wrong electrically causing the points to arc.

Done right a dist should be good for several generations of your family without being touched much other then lubing and the occasional points adjusting.

Anyway, just a few things to consider.