Its not all that uncommon for the mechanical advance in these distributors to be functioning poorly or not at all after 60 plus years. You can take the distributor apart to a pretty good degree (but not completely unless you remove the gear). Most of the obvious issues will usually turn up, excessive crud, broken pins, broken or missing springs, rust, frozen advance weights. So a good cleaning, lubrication where needed and reassembly many times will do the trick. That being said, the only real way to confirm whether you got it is to put the distributor on a Sun, or Allen or King distributor machine and test it out.
I just finished a rebuild a couple of weeks ago. Without taking it apart or cleaning, the mechanical advance was not coming in when it should have been about 1200 engine rpm late (Sun 404 machine). I took it apart, rust and crud and a lot of it, and one partially frozen weight that hardly moved. Once I had it clean and rebuilt, I put it back on the Sun distributor machine and discovered it was still not coming in correctly, still a little bit late. Swapped the springs from another distributor and finally got the mechanical advance to come in on time. But you need a distributor machine to really get this right. If your mechanic has one, you are all set.
Notwithstanding, you might very well consider the other advice you have received here and get a new set of wires on, and a fresh tune up, cap, rotor points and condenser. All low hanging fruit that will not hurt to do even if its not needed.
As for HEI, its a great ignition. Tom Langdon at Stovebolt Engine Co. sells the S-10 conversions all done and ready to install. You will need to do some wiring to get it to work properly. On the other hand, the points are reliable, easy to work on, and if any part of the ignition does let you down, its an easy fix. I run a points distributor in my very modified 261 motor, never misses a beat.
Last edited by Dragsix; 06/21/2018 7:07 PM.
