Install HEI in 74 Big Block
Thread Starter
Drifting
Joined: May 2005
Posts: 1,909
Likes: 6
From: Lake Arrowhead - Georgia > 72 Base Coupe & 74 BB Roadster
Install HEI in 74 Big Block
It should be simple. 
Just run a 12 gage wire from the IGN post on the fuse block to the batt plug of the HEI. The HEI unit grounds itself to the block via the tighten down bolt..(?) I thought that was the way to go. ??????? It will not fire until the very last second when I release the switch from start to run. The HEI is not being powered while the starter is engaged.
The tach terminal on HEI is empty since I have a mechanical drive tach. How have I screwed this UP?
Where should I power the HEI from. Easiest route would be the resistor wire(s) (there's TWO) but I've been told the HEI needs the full 12 volts.
Any help here?
Just run a 12 gage wire from the IGN post on the fuse block to the batt plug of the HEI. The HEI unit grounds itself to the block via the tighten down bolt..(?) I thought that was the way to go. ??????? It will not fire until the very last second when I release the switch from start to run. The HEI is not being powered while the starter is engaged.The tach terminal on HEI is empty since I have a mechanical drive tach. How have I screwed this UP?
Where should I power the HEI from. Easiest route would be the resistor wire(s) (there's TWO) but I've been told the HEI needs the full 12 volts.
Any help here?
Le Mans Master
Joined: Oct 2006
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From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
The pair of wires that went to the coil- one is the resistor wire and the other goes to the solenoid for 12v when cranking. And you are correct in your thinking. Sort out which one of the two wires goes to the solenoid (some have a yellow cloth-looking insulation) and tie that and the new wire together to the HEI. That will give you power when the key is in the RUN position and when cranking.
Thread Starter
Drifting
Joined: May 2005
Posts: 1,909
Likes: 6
From: Lake Arrowhead - Georgia > 72 Base Coupe & 74 BB Roadster
The pair of wires that went to the coil- one is the resistor wire and the other goes to the solenoid for 12v when cranking. And you are correct in your thinking. Sort out which one of the two wires goes to the solenoid (some have a yellow cloth-looking insulation) and tie that and the new wire together to the HEI. That will give you power when the key is in the RUN position and when cranking.
Thanks Tim .... literally just did that! It worked just as you say!
I put a nice "plug" end with some heat shrink on the two wires and plugged into the BATT terminal on the HEI. Fired right up.
Last edited by fotyfobravo; Mar 19, 2017 at 08:22 PM.
Thread Starter
Drifting
Joined: May 2005
Posts: 1,909
Likes: 6
From: Lake Arrowhead - Georgia > 72 Base Coupe & 74 BB Roadster
