One out of a junked GM car from the 70's or 80's. The factory ones from GM last a lot longer than the aftermarket ones.
I was lucky enough to have a couple of OEM AC Delco modules left over for a couple of projects. 15yrs, no failures. We've had a couple of customer cars using Pertronix III modules that have performed well for several years. Some of the cheap offshore modules are not so good. Beware of those. If you're mounting it outside the distributor, use a heat sink and thermal paste.
I have been using the modules from NAPA. They have two different 4pin modules. I've used both. I do carry an extra as they are not always in stock, over the counter.
Always put dielectric grease on the base of the module when replacing those... Helps with heat transfer...
and make sure you get the connectors on properly, it's possible to "miss" and put the male terminal between the female terminal and the plastic housing...and then you get all kinds of fun intermittent issues.
Original modules work a long time; make sure you use thermal transfer paste when mounting them to the plate or heat sink. I mounted one I had in the toolbox, on a GM heat sink available on Vortec engines and Amazon, with thermal paste between layers and now firing the Duraspark distributor in the 351W.
Napa Echlin TP45 Is the better of the two napa modules. I'd have to agree that the old original Delco units salvaged out of an old distributor are probably the best ones. My experience says that if an HEI module goes out it is usually something else down stream that is the actual cause.
Read this.........available at Amazon for about $25, and you will be able to make a good choice on what you want to do. It will familiarize you with the differences in HEI thru the years so you can get the best set up. Might find a used one on Ebay cheaper.
Dielectric grease or thermal paste? I use thermal paste made for electronics and computers Dielectric grease is used where I don't want water to go.
Try this.. I have used them and they work great... but is a pretty tight fit in the body of the distributor https://www.summitracing.com/search...OI0C-94W6kplcBLiCVrY5VJrcRMF46aBoCBwoQAvD_BwE
Thermal paste preferably, but it seems lots of substances can do the job well enough to be very useful. Here's a test on the CPU of a computer including a bunch of crazy things, everything but chocolate cools better than no paste at all it seems. I'd stick with something that doesn't dry out, so no mayonnaise, toothpaste or such - grab something out of the garage, not the kitchen.
I ran stock points in the stock cars, always Accel or Blue Streak. Anything else would break up north of 6000 RPMs.
you're original question was what was the best module for an HEI---IMO it would be the old stock 900 series modules from Delco. They were built to last, not replace.
Also if you are shopping for old original modules, it's good to know the Delco date code system. You're on your own to figure out the decade of the part, although the 4 pin modules were mostly only used from 75-mid 80s. The date code is like 9 B 15 where 9 is the last digit of the year (ie. 1979) B is the month, since B is the second letter it's February 15 is the day of the month, here the 15th of Feb 1979. As an added bonus, this date code system was used on distributors, starters, and generators during the HAMB era.
The Jalopy Journal
