Been considering running an HEI distributor. As i understand it and my questions are, It needs a full 12 volts therefore you can not use the wire that's there for a stock distributor as it's designed to drop voltage, right? As I understand it the power supply needs to supply a full switched 12 volts, right? If that's the case and I have a supplemental switched distribution block on the firewall. What size fuse would I need to use in this box for the line running to the HEI and what size wire? The supplemental distribution block is rated at 100amps and I currently have 50 amps connected to it. TIA Pete

If you don't want to change out the original resistor wire, why not use something like this and plug it into the IGN terminal in the original box. Doesn't change anything. That's the same point as the original distributor wire feeds from. About a ten minute job. I poke a hole through those plastic grommets that hold the carpet to the firewall and clamp a 1/4 inch spade lug on the wire after it's fed through. It's a 20 amp fuse.

EDIT:
Page is not coming up today. It's called the hei1 in the catalog. Other people carry items like this.

http://www.centechwire.com/catalog/...ries/hei1.shtml

John,
The ignition terminal already has two wires occupying it and since I already have the supplemental block there I thought I'd use it. Plus how many "things"can you have coming off the ignition terminal anyway? Thanks as always Pete

Maybe move something off IGN and over to ACC, depending on what it is.

If memory serves me right it's the tach wire and the supply wire for the supplemental block. I'll have to check tonight to be sure. Thanks Pete

THE EASY WAY TO DO THIS:

- Trace the white wire from the coil to the fuse block. Cut the white wire (cotton covered) ignition wire 2-inches from the firewall plug. This is the previous resitor ignition wire for the points.

- Splice (or solder and heat shrink is my preferance) a new coper 12 or 14 gauge wire to the end of this white wire stub. The new wire should be cut to length from the fuse block to the HEI.

- Install an HEI plug or spade plug (generic yellow terminal) to the end of the wire for connection at the "BAT" terminal at the HEI. New HEI plugs can be had from Summit Racing for about $5. The green tach wire will go to the "Tach" terminal with the same type spade plug.

Now the HEI will function in normal manner being "Ignition Fused Hot" and activated by turning the ignition key to "Run".

The yellow wire that used to go to the coil will no longer be needed. This wire used to be needed for a "Full 12-volts" during start-up. This wire can be removed from the coil to the "S" starter lug. The purple wire will remain on the starter solenoid ("R") from the ignition switch.

I have used this method of wiring for about 15 - 20 years now. I learned this trick from an old Car Craft tech article from the mid 80's.

Good Luck. :D

Thanks for the replys. Our goal is to leave the factory wiring intact and not cut it or remove anything if at all possible. We prefer to tape up and hide unused wires just in case down the road someone might want to return it to factory. Crazy yes, but what we prefer to do. Thanks Pete and Nicholas

Pete, removing the resistor wiring from the bulkhead connector is one thing. Soldering to a piece of the original resistor wire is another. That wire is not solderable because it's not copper. A standard SN63 tin/lead solder won't form a true solder joint. It only "glues" to the original wire which leads to problems down the road.
And if someone in Car Craft said you can solder to the resistor wire, have him email me. He's not so smart and needs to read up on metallurgy basics.

You could remove the terminal at the firewall bulkhead connector and install a new terminal with a new 12 gauge wire in its place to supply the HEI. Then tape the old terminal and the resistor wire out of the way. At least this way you won't be permanently modifying the factory wiring. IMO, that's the best way to do it anyway.

Larry