Bill, I have had more magnetic pick ups go bad on me than anything else. On the 2 HEI's that I used, both had an intermittent no spark which I could remedy by moving the pick up wires around. You have to remove the distributor to change them though.
Keep in mind that the problem can be intermittent. The wires only show a problem when they get moved.
Keep in mind the heatsink compount for the module should be a very thin layer, just enough that you might still see a bit of metal shine through here and there. You are not frosting a cake! Too much can be worse than none at all. Also take a razor blade and a some solvent and clean the old stuff out of the housing. Pickup coils should be a low failure item but they do fail and have a habit of being an intermittent fail item so diagnosis can be a bit tricky. Gives you a good excuse to pull the the distributor and clean it up though and the parts aren't expensive so there are worse things in life.
Here’s what I would do, from a simplistic viewpoint. Use a test light, crank the engine and see what the tach signal is doing. You can pop the coil cover off if you don’t have a jumper lead. If the light is on steady when cranking, put a module in it. If that doesn’t do it, put a pick-up coil in it.
I finally got a chance to check out a few things. I did get 833 ohms on the pickup coil, but also got some bad readings when moving the wires. The rest of the wires in the unit look suspect and are what, 40 years old. So I am looking at more parts and wires. Looks to me like the $99 TA HEI would be the most value and have the correct timing curve as well. Recommendations/Opinions?
https://www.davessmallbodyheis.com/ A little more money but well worth it. Reading up on Dave's site, he might not be back to work yet. https://www.davessmallbodyheis.com/services/please-note-recent-health-issues
I would rather have a "good used" or repaired Genuine GM HEI than a brand-new Chinese HEI. The timing curve would likely need to be optimized to your engine in either case--although I don't know what the curve of the TA unit is.
TA HEI has 22* of mechanical advance, starts at 1000 RPM, all in at 3400 RPM. Comes with adjustable vacuum advance. It is most definitely Chineseum though.
Oh man - Dave got a spider bite. Anyone who has had or knows someone who has had one of those knows how bad they can be. Yeah, he's down for awhile. Best wishes for a good recovery, Dave! OK, its chineseum, but it is from TA and I have not heard any bad things about them.
Anything that you would need to “rebuild” yours would likely be sourced from China anyhow, unless you could find some old parts. Obviously the ignition module and pick-up coil would be the critical ones.
OK, I've been shamed into rebuilding mine - never take the easy way out! lol! What spring package do you recommend for an HEI? I'm looking at the summit one as I just need the springs: https://www.summitracing.com/parts/sum-g5212 . I will limit the vac advance with this: https://www.summitracing.com/parts/msd-84281 .
https://www.summitracing.com/parts/msd-84281/reviews Never saw that before, but the reviews are good. You can also use the Crane Kit. Personally, I like the springs in it better. https://www.summitracing.com/parts/...MI79aNieCf6QIVRpyzCh1Xawy4EAQYASABEgLlv_D_BwE If you choose the Crane kit, just mount the cam ahead of the link like this, It involves drilling and tapping the arm. Kenny Gies also makes plastic vacuum advance limiters, http://v8buick.com/index.php?threads/new-product-vacuum-advance-limiter-bushings.346184/
Hi Bob - I had to take it apart to get to the pick up coil so rather than put it all back together and trouble shoot more I decided to "rebuild" with all new components. The bushings feel good and the weights move well so I think I'm good. I'll add a limiter to the vac advance and go to lighter springs. It's a stock 350 dist. I'm going with DUI coil and module, every thing else is Delco. So I am currently waiting for parts to arrive. I'm sure I'll have questions when it goes together. Thanks!
It's going back together and I see there is a grease reservoir under the pickup coil for the upper bushing. What do you guys use? I've seen various answers online and the GM stuff is very expensive...if you can find it. Update: I also asked Dave from small body hei - he said use wheel bearing grease in the reservoir and a few drops of oil on the felt. Thanks Dave! https://www.davessmallbodyheis.com/
Some progress: This is the grease reservoir. It is under a thin plastic cap. Be very careful removing the thin cap as it is fragile: The coil is held in with a small thin C-clip: