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Received my GM style HEI Distributor Saturday for the ‘62 C-10 235. The distributor has already been set up for the 235 so it’s just a drop in. The instructions tell how to get the engine to TDC (as if I didn’t already know) but they assume you are replacing not converting. I think I know the answer to my question but I just want to double check. There are the standard two connections (ign/tach) and no others. I’m thinking the wire to the positive side of the existing coil (which goes away) goes to the ign plug on the distributor. Am I right or wrong? BTW I’ve been wrong twice today according to my wife.🛠

When you get it working, please come back here and tell folks where you bought the HEI distributor?

You will need a BIG wire to the "ign" terminal on the distributor cap, all the way from the ignition switch to the distributor- - - - -12 gauge minimum, and 10 would be better. Most likely, the wire from the switch is around a 16 GA or smaller, and it might possibly be a nickel/chrome resistance wire that drops voltage like a ballast resistor used to. I don't remember what year GM started using the nichrome wire, but it was somewhere in the late 1960's I believe. The HEI coil needs a lot of current, especially on a cold start.
Jerry

I believe that you can fry that thing by putting 12v to the wrong terminal...... so be careful!

Jerry, that's just what I needed. Dave, the terminals are labeled so if I wear my glasses I should be ok.

Actually, the GM HEI is pretty much idiot proof. Connecting 12V to the Tach terminal doesn't hurt it- - - - -the spark just doesn't happen. Some of the aftermarket electronic ignition systems fry themselves if you sneeze at the wrong time!
Jerry

Weather is not going to cooperate for a week or so and I don’t have an inside shop so the install is on hold.🛠

Well the weather cooperated today so the install was on. Took about an hour mostly removing the old stuff and brackets. The new HEI was a fairly straight up install. Only one wire to make up. Had the engine on #1 TDC, set the new housing into place and bolted the hold down in place. The cap took a little fiddling to get right since the system is the large cap style and the push rod cover is less than 1/32 inch away. It did fit w/o modifications. Cranked it over and with a little fine tuning of the timing she fired right up. The brand is TSP model #JM6516R. Price is fair. Sold through Amazon by HPREngines. I’ll do a driving report this weekend.🛠

Starts, runs and drives well.😀

I found the TSP model #JM6516R unit on Amazon and it looks just like the one Summit sells but for the red cap. I see it is one wire. Are there directions telling how to hook it up? What about a tach wire? I have an Autometer tach that I would like to use. What is a good ignition wire set to use with it?

Paul, one wire from ignition. If you want to run a tach there is a second (labeled) terminal on the distributor. The directions with the unit are in American but lack a diagram or much detail. Guess they figure if your ordering it you know how to install it. You can get a wire set from any FLAPS or search Amazon for 6 cylinder HEI plug wires. I found red ones to match the cap. 🛠

I think i found the answer with the tach. There is a special plug with two wires. One for the one wire system, the other for the tach. The one I found is NEW HEI Distributor Wire Harness Pigtail Dual 12v Power and Tach Connectors 170072. Will that work?

I also found an ignition wire set: HEI Spark Plug Wire Set for 1941-1962 Chevy Chevrolet Inline 6 194 216 235 Oem Fit PWJ132. This sounds like it might be right for the HEI dizzy.

This is a one wire system. Does that wire go to the ignition switch?

Thanks Martin, that is pretty much what I needed to know about this unit. I like the idea of a new dizzy rather than trying to upgrade ny old one which might be worn and will certainly need new bits.

The wire goes from the hot when on side of the ignition switch. You will need to run a 14ga or 12ga wire. I used 14ga on mine. I just used a female spade connector when doing mine since I don’t have a tach.🛠

Do these HEI units use the stock plugs? If so, what gap?

Stock plug will work fine. Gap at .045.🛠

8 or 10 guage wire to supply the HEI, no 14 or 12 guage.

Ed

OK, from the switch to the dizzy, heavy wire. It seems that the wire TO the switch from ammeter negative and on to the starter terminal (?) will also need to be heavy? This is all still a bit fuzzy in my mind . . .

The way the coil develops more firing voltage capacity is by building a better magnetic field around the windings. This is done by flowing more primary coil current than a set of points can handle. Without getting deep into the physics and electronics of induction coil operation, the more primary current there is, the hotter the spark will be. Points can handle around 5 amps without overheating and burning. A HEI coil carries around 15 amps, sometimes more as the current first begins to flow. It does this by using heavy duty power transistors instead of points.

The primary wiring from the battery, through the ignition switch, to the coil has to be capable of flowing the increased primary current, so yes, the entire circuit needs to be upgraded, not just the wire from the switch to the coil. The circuit from the positive battery cable to the ignition is usually pretty heavy to begin with, because it carries the current for accessories like electric wipers and the heater blower as well as the ignition, in most cases. It doesn't hurt to run a new, heavy wire with very good terminals there, however.
Jerry

awesome thanks all