HEI conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cfinance · 09-04-2006, 10:56 AM

Hey, there.
Purchased a '71 C-10, 350 w/ 4-speed that appears all stock. Considering a conversion to HEI distributor for performance and fuel benefits. Existing coil is separate from the distributor (stock setup, I believe). Where would plactic electrical connector from top-mounted coil on HEI distributor plug into? Three different answers from parts store ranging from "clip it off" (no), to "need to be wired directly to ignition". Existing wiring in engine is really hacked up. Amazing it still drives (and great, too). Good advice and sources appreciated.
Would post pictures, but this one looks better in candlelight!

byrd · 09-04-2006, 10:59 AM

Run from ignition to new HEI, old wire has a resitance value to it and you won't get full voltage to the HEI.

Americanrider · 09-04-2006, 06:09 PM

Another wet-side truck bro.... I drive a "20footer" too. Here is the HEI info your looking for:

http://67-72chevytrucks.com/vboard/s...ad.php?t=13698

*72lb4x4* · 09-04-2006, 10:54 PM

A couple bits of info useful to those who have trucks that aren't wired normally, or thos whose POs have gotten creative with...

The resistance wire has (or mine does) a fabric sheath around it, and its one down from the top left in the firewall plug. That's assuming that the tan wire that connects to the brake proportioning valve is in the top left. The wiring diagram for my 72 says its pink and black but the outer fabric is actually white after thirty odd years.

The location of the connector in the firewall plug is useful if you want to remove the R-wire and replace it with the #12 (with fuse) needed rather than run another wire. If you go this route, its more work, but the result is better.

BTW: wiring harness tape is available from Eastwood, etc. and is better than electrical tape. Wiring harness tape is wider and not sticky on one side. The original harnesses used this tape. At the start of the wrap, black duck tape was used to hold the tape in place.

My truck has had several mods done all in red 12AWG wire and I still have a few to get rid of, including the HEI and starter solenoid. I was looking at the harness today, but my skills with the camera are nonexistent so the pics are furry.

cfinance · 09-05-2006, 11:41 AM

Thanks for the quick posts and guidance. Lots of HEI strings to read and Chevy gurus to learn from.

krue · 09-05-2006, 12:49 PM

Welcome to the board!

**VetteVet** · 09-05-2006, 06:47 PM

[QUOTE=My truck has had several mods done all in red 12AWG wire and I still have a few to get rid of, including the HEI and starter solenoid. I was looking at the harness today, but my skills with the camera are nonexistent. SO THE PICS ARE FURRY.]QUOTE]

sorry I just couldn't resist.LOL

Jimbotronics · 09-05-2006, 08:35 PM

Also dealships still carry the spade clips that snap into the fuse box. So does Napa, but the Napa closest to me would only sell me 'em by the box - didn't need fifty of 'em..

09-04-2006, 06:09 PM	#3
Americanrider Registered User Join Date: Dec 2004 Location: NW, WA. Posts: 1,421	Re: HEI conversion Another wet-side truck bro.... I drive a "20footer" too. Here is the HEI info your looking for: http://67-72chevytrucks.com/vboard/s...ad.php?t=13698

09-04-2006, 10:54 PM	#4
72lb4x4 Account Suspended Join Date: Jul 2006 Location: DFW Posts: 1,427	Re: HEI conversion A couple bits of info useful to those who have trucks that aren't wired normally, or thos whose POs have gotten creative with... The resistance wire has (or mine does) a fabric sheath around it, and its one down from the top left in the firewall plug. That's assuming that the tan wire that connects to the brake proportioning valve is in the top left. The wiring diagram for my 72 says its pink and black but the outer fabric is actually white after thirty odd years. The location of the connector in the firewall plug is useful if you want to remove the R-wire and replace it with the #12 (with fuse) needed rather than run another wire. If you go this route, its more work, but the result is better. BTW: wiring harness tape is available from Eastwood, etc. and is better than electrical tape. Wiring harness tape is wider and not sticky on one side. The original harnesses used this tape. At the start of the wrap, black duck tape was used to hold the tape in place. My truck has had several mods done all in red 12AWG wire and I still have a few to get rid of, including the HEI and starter solenoid. I was looking at the harness today, but my skills with the camera are nonexistent so the pics are furry. Last edited by 72lb4x4; 09-04-2006 at 10:55 PM.

09-05-2006, 11:41 AM	#5
cfinance Registered User Join Date: Aug 2006 Location: Port Orchard, WA Posts: 122	Re: HEI conversion Thanks for the quick posts and guidance. Lots of HEI strings to read and Chevy gurus to learn from.

09-05-2006, 12:49 PM	#6
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,448	Re: HEI conversion Welcome to the board! __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

09-05-2006, 06:47 PM	#7
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,719	Re: HEI conversion [QUOTE=My truck has had several mods done all in red 12AWG wire and I still have a few to get rid of, including the HEI and starter solenoid. I was looking at the harness today, but my skills with the camera are nonexistent. SO THE PICS ARE FURRY.]QUOTE] sorry I just couldn't resist.LOL __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative. Last edited by VetteVet; 09-05-2006 at 06:55 PM.

09-04-2006, 10:56 AM	#1
cfinance Registered User Join Date: Aug 2006 Location: Port Orchard, WA Posts: 122	HEI conversion Hey, there. Purchased a '71 C-10, 350 w/ 4-speed that appears all stock. Considering a conversion to HEI distributor for performance and fuel benefits. Existing coil is separate from the distributor (stock setup, I believe). Where would plactic electrical connector from top-mounted coil on HEI distributor plug into? Three different answers from parts store ranging from "clip it off" (no), to "need to be wired directly to ignition". Existing wiring in engine is really hacked up. Amazing it still drives (and great, too). Good advice and sources appreciated. Would post pictures, but this one looks better in candlelight!

09-05-2006, 08:35 PM	#8
Jimbotronics YA YA Join Date: Aug 2004 Location: Rockledge, Fl Posts: 1,273	Re: HEI conversion Also dealships still carry the spade clips that snap into the fuse box. So does Napa, but the Napa closest to me would only sell me 'em by the box - didn't need fifty of 'em.. __________________ Jimbo '72 SWB - 350 (frame-off resto in progress - donations accepted) '04 Chevy Avalanche '03 Cadillac CTS (wife's ride) Restoration progress - http://67-72chevytrucks.com/vboard/s...d.php?t=335707



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