I heartily second what Jerry said. He may be talking about me. I deconstructed one of their epoxy-molded "ignitor" units (given to me by a friend after it failed miserably). Carefully took it completely apart. There might (and I emphasize the word might) be something like $3 to $5 worth of stuff in there and that's it. A Hall Effect sensor and a magnet with 8 segments that fit over the distributor lobes. A resistor or two. That is your "ignitor" in a nutshell. Something a jr. high kid in a science class might invent. In my opinion this is a horrible excuse for an ignition product and a tragic ripoff. The FACT many people carry a points distributor under their seat (and suggest everyone do this) when they travel should answer any questions about dependability. Think of it this way: let's say a new type of tires was being sold which promised to make your truck drive really nicely at any speed but they cost a lot more money. And there were scads of people (just on this one site) who said "okay, buy them if you must but never leave the house without carrying 4 normal tires so you can get home when those fail." Would you feel good about buying them?
A year or year and a half ago I showed exactly how to convert one of the Chinese HEI distributors made for the Chevy 230-250 for use on the 235. It will cost you about $100 or less to do this, includes the matched coil and you only need a hacksaw, a bench grinder and a collar to attach to it. Even though it was made in China and even though it is ugly, you can use GM components in it and even with the Chinese parts I promise you it will be more dependable than anything labeled Pertronix. I'm using one of those on my truck right now and it is just fine. I bought it in 1997 and have had no trouble with it.
Good luck! You can get the Chinese distributor in three colors...black, blue, red. Attached is an image (note you get a brand new vacuum advance canister, too)
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
