I know Tom pretty well. I still have a lot of the written correspondence that he and I engaged before he retired from GM and before he took over Stovebolt Engine Company, all pre internet. If you have ever seen a list of like 4 or 5 235/261 casting numbers with corresponding combustion chamber volumes, that was a list I posted on the inliners site many years ago now after Tom and I were talking on the phone and he looked them up in the GM archives right while we were talking. He is a tremendous resource.
That being said, and I can hardly believe it myself, Tom is 80 now.
Fairly recently I purchased the last HEI that Tom had. He sold over 3000 of them over the years. Tom purchased all of the S-10 cores he could lay his hands on and there are just no more available. Originally he was modifying the shafts, but later was using custom made shafts because the quality of the cores, and in particular the shafts, was becoming an issue.
So it’s not likely any more new “Langdon” HEI units will become available. And I imagine that at some point, Tom will likely want to hang his spurs up. it’s probable that if you keep your eyes open, a used unit may come up for sale.
As for Petronix, it’s just a different way to trigger the coil. Works essentially like a set of points. Some who have used them swear by them. Others, have not had a positive experience with them. But the thing is, a Petronix converted distributor is not a high performance ignition.
On the other hand, an HEI is, and is probably one of the very best designs ever. If you really want a good reliable non-point ignition that uses modern parts (relatively speaking, lol) available without a lot of fuss or muss, I think you would be hard pressed to find a better ignition.
As for converting a stock 235 distributor to HEI, I know that Jim Linder at Bubba’s Ignition use to do conversions. What I don’t remember is whether his was a Mopar trigger and gm module or gm trigger and module. Jim is either very semi retired only doing flat head ignitions, or he is completely retired. He had been recently beset with some unfortunate health issues so it would not surprise me that he has fully retired.
Deve at Deve’s Technet I think still has his kits available using a Mopar reluctor, GM trigger and GM module, along with a plate that installs over the original point plate. I have Deve’s parts to do a conversion, just have not had time to actually convert one but if his YouTube video is any indication, it works pretty good.
Last edited by Dragsix; 06/17/2023 1:34 AM.
