HEI dist in 4x4 72 Jimmy/Blazer - The 1947 - Present Chevrolet & GMC Truck Message Board Network

John H. · 10-08-2009, 01:37 AM

Can you install one without any clearance issues with the firewall?

*2tons of fun* · 10-08-2009, 03:14 AM

yup

**special-K** · 10-08-2009, 05:36 AM

Yeah,but she sure is tight,huh?No clearance problems,just very tucked in back there.

TonyJohnson · 10-08-2009, 10:50 AM

Issues? Yes, it's tighter than hell. Had to build a special tool to get to one of my hold downs. Was it worth it? Hell yeah...

**jaros44sr** · 10-08-2009, 01:02 PM

I'm thinking BFH

...can you say 6 gallons of sh!t, in a 5 gallon bucket

chalet2506 · 10-09-2009, 04:05 PM

I put summit part # 850001R in my 72 Jimmy, no clearance issues.

Sacramento70 · 10-10-2009, 09:20 PM

im in the process of installing HEI in my blazer as well, when i finish ill take some pics and show what it looks like and how long it took.

Long Roof · 10-10-2009, 10:26 PM

Mine has one and I didn't think it was to tight. Surely seen worse.

John H. · 10-11-2009, 10:47 PM

Thanks everyone for the responses. I just ordered new wiring harnesses for the HEi and for an in ternal voltage regulator alternator. I will start a build thread soon.

RckyMntnKng · 10-12-2009, 12:55 PM

Sorry not meaning to hi-jack....

On the topic of HEI conversion, what do you need to do with the plug gap if anything?

**jaros44sr** · 10-12-2009, 12:58 PM

Quote:

Originally Posted by RckyMntnKng

Sorry not meaning to hi-jack....

On the topic of HEI conversion, what do you need to do with the plug gap if anything?

open it up to .045

My fingers just slide behind the spark plug wires boots locking ring...finger measures 3/4 to 1 inch, if you take off the locking ring you might gain 1/4 to 1/2 inch, but Accel doesn't recommend it

RckyMntnKng · 10-12-2009, 01:06 PM

Thank you.

Considering you would just buy all new plugs wires and HEI and do them together....

Is there a difference in just getting new stock plugs at .035 and opening them to .045, or find stock set maybe for some other year with the same thread and depth and the gap already at .045?

Id love someone to post the AC/Delco part number to look for. Im currently adding a 65000k HEI and 10mm wires...plugs are last item.

Is there any tricks to the install for all 3? Never done a points conversion before. I already changed out the ALT for a Internally regulated.

Thanks

**jaros44sr** · 10-12-2009, 01:20 PM

Mine were ordered as '74 corvette wires w/ramshorn manifolds from Accel...stock size wires are 7mm, but 8mm just go into the factory wire holders.

I may be reworking the lenght of the wires, just haven't got aroundtoit

plugs would depend on how your engine is built and runs...hotter or colder spark, but basically stock

truckster · 10-12-2009, 11:45 PM

If my memory serves me, the stock plug for the 350 with HEI is a Delco R44TS.

Cap'n Hook · 12-12-2009, 11:26 AM

Quote:

Originally Posted by truckster

If my memory serves me, the stock plug for the 350 with HEI is a Delco R44TS.

My Jimmy's Goodwrench 350 has Delco CR43TS. What's the difference if any? And yes it has HEI.

bouncytruck · 12-12-2009, 02:48 PM

I had one in my 69. It was tight but cleared the firewall by about 1/8 inch.

Firebirdjones · 12-12-2009, 04:28 PM

The AC plug R44TS is simply the small 5/8 plug with a taper seat and extended tip.
T=taper seat
S=extended tip

GM started using these plugs in both big block and small block chevrolets in 1971 and work in pretty much anything up through the late 80's with a cast iron head that doesn't require more reach.
You can go as cold as 43's which is what I run in a couple of cars, but that heat range is getting harder to find. Seems the 44's are also getting scarce. You can go as high as 46's if you wish.
Most parts stores want to sell you the 45's it seems.

For stock or nearly stock engines and close to sea level, I'd shoot for the 44's and go from there.

As far as the HEI's, they are a cheap alternative to electronic ignition. Very dependable. The downfall is the size for me. I never liked the bulkyness and the amount of crap you have to remove for a simple cap and rotor change.
I'm an MSD person myself, used them for 20 years without a hickup. They can be made to look stock as well, if you are into the stealthy stuff.

But a good setup is 5 times the price unfortunately.

swyfor5 · 12-12-2009, 10:30 PM

Very interesting topic, as I am looking at upgrading on next rebuild. Currently running the point dist, and time for a change! What wiring changes have to be made?

cparman · 12-12-2009, 10:37 PM

My Blazer had an HEI in it when I bought it. I have a bunch of clearance??? Her is a poor pic of it. I think I can get my hand around it no problem. Oh yea, i used a set of Taylor wires that I cut to length. I ran the front two on both sides under the motor mount. ( like a Corvette with HEI ) I have done this a bunch of times with Rams horn manifolds. Looks good, and makes teh wire set look very neat.

pound41 · 12-12-2009, 10:42 PM

mallory unilite is about same size as stock and uses the OE style wires

Firebirdjones · 12-13-2009, 12:23 PM

Quote:

Originally Posted by swyfor5

Very interesting topic, as I am looking at upgrading on next rebuild. Currently running the point dist, and time for a change! What wiring changes have to be made?

Well, what I do when converting an old car to electronic is pull the main bulk head from the firewall.

GM used a resistance wire that ran from this bulkhead to the positive side of the coil. I have a stockpile of those factory connections used in that bulkhead.
I simply remove that resistance wire from the bulkhead, and use another factory connector with a 10-12 gauge wire. And simply re-route that through the harness up to the positive side of the coil.

Sometimes, depending on the car, I'll keep that resistance wire in the harness as well (connected to the bulkhead but hidden inside the harness) just in case I decide to switch back to points for any reason.
Keeps everything neat and factory appearing.

You don't have to worry about the other side of the bulkhead that runs to the fuse box and ignition switch. GM used all standard wire on that side. The resistance wire was only installed from the bulkhead to the coil.

Keep in mind this is GM only. Other brands such as Chrysler used a simple resistor mounted on the firewall.

Firebirdjones · 12-13-2009, 12:28 PM

Quote:

Originally Posted by cparman

My Blazer had an HEI in it when I bought it. I have a bunch of clearance??? Her is a poor pic of it. I think I can get my hand around it no problem. Oh yea, i used a set of Taylor wires that I cut to length. I ran the front two on both sides under the motor mount. ( like a Corvette with HEI ) I have done this a bunch of times with Rams horn manifolds. Looks good, and makes teh wire set look very neat.

Not only does that wire routing keep things neat,,,,that's actually the way the wires were supposed to go when using those ramhorn manifolds. It was done on some trucks as well as passenger cars.
There are factory wire supports that mount to the block near the motor mount as well as on the rear of the block next to the transmission bellhousing that holds all the wires together.

Last time I did this setup there were several restoration vendors that still sold these factory wire looms.

**jaros44sr** · 12-13-2009, 01:22 PM

Quote:

Originally Posted by cparman

My Blazer had an HEI in it when I bought it. I have a bunch of clearance??? Her is a poor pic of it. I think I can get my hand around it no problem. Oh yea, i used a set of Taylor wires that I cut to length. I ran the front two on both sides under the motor mount. ( like a Corvette with HEI ) I have done this a bunch of times with Rams horn manifolds. Looks good, and makes teh wire set look very neat.

Man Parman, that engine bay and motor look like crap!

J/K, nice attention to detail and workmanship, but I don't know why I have such little clearance

**jaros44sr** · 12-13-2009, 01:26 PM

Quote:

Originally Posted by Firebirdjones

Well, what I do when converting an old car to electronic is pull the main bulk head from the firewall.

GM used a resistance wire that ran from this bulkhead to the positive side of the coil. I have a stockpile of those factory connections used in that bulkhead.
I simply remove that resistance wire from the bulkhead, and use another factory connector with a 10-12 gauge wire.

Do you have any pics of removing the wires from the bulkhead connector, always wanted to know how to do that...special tools?

bouncytruck · 12-13-2009, 01:28 PM

Quote:

Originally Posted by cparman

My Blazer had an HEI in it when I bought it. I have a bunch of clearance??? Her is a poor pic of it. I think I can get my hand around it no problem.

Is your Blazer 2wd and the engine mounted in the forward 2wd position?

10-08-2009, 01:37 AM	#1
John H. Registered User Join Date: Oct 2007 Location: Sammamish, WA Posts: 2,115	HEI dist in 4x4 72 Jimmy/Blazer Can you install one without any clearance issues with the firewall?

10-08-2009, 03:14 AM	#2
2tons of fun Account Suspended Join Date: Jan 2009 Location: galt ca, Posts: 749	Re: HEI dist in 4x4 72 Jimmy/Blazer yup

10-08-2009, 05:36 AM	#3
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: HEI dist in 4x4 72 Jimmy/Blazer Yeah,but she sure is tight,huh?No clearance problems,just very tucked in back there. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

10-08-2009, 10:50 AM	#4
TonyJohnson Registered User Join Date: Mar 2003 Location: Cheboygan, MI Posts: 998	Re: HEI dist in 4x4 72 Jimmy/Blazer Issues? Yes, it's tighter than hell. Had to build a special tool to get to one of my hold downs. Was it worth it? Hell yeah... __________________ Tony Johnson -- '71 Blazer w/L-31 Vortec 350, SM465, NP205, performer intake, edelbrock 1406, HEI, 4" lift, Boyd EFI tank, Vintage A/C My Blazer --

10-08-2009, 01:02 PM	#5
jaros44sr Senior Member Join Date: May 2006 Location: Philadelphia, Pa. 19454 Posts: 9,768	Re: HEI dist in 4x4 72 Jimmy/Blazer I'm thinking BFH...can you say 6 gallons of sh!t, in a 5 gallon bucket __________________ Semper Fi...Uncle Sam, you da man All parts offered to help are free, unless otherwise noted Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training SAFETY FIRST AS usual, off topic They say your mind goes second, can't remember the first Jim Last edited by jaros44sr; 10-08-2009 at 01:04 PM.

10-09-2009, 04:05 PM	#6
chalet2506 Registered User Join Date: Nov 2008 Location: DFW, Tx Posts: 39	Re: HEI dist in 4x4 72 Jimmy/Blazer I put summit part # 850001R in my 72 Jimmy, no clearance issues.

10-10-2009, 09:20 PM	#7
Sacramento70 Blazer Fanatic Join Date: May 2009 Location: Sacramento, ca Posts: 249	Re: HEI dist in 4x4 72 Jimmy/Blazer im in the process of installing HEI in my blazer as well, when i finish ill take some pics and show what it looks like and how long it took. __________________ 1970 Chevy blazer

10-10-2009, 10:26 PM	#8
Long Roof Old School, New Style Join Date: Jun 2005 Location: Monroeville, Ohio Posts: 790	Re: HEI dist in 4x4 72 Jimmy/Blazer Mine has one and I didn't think it was to tight. Surely seen worse. __________________ The Good: - 72 GMC Jimmy 4x4 - 307 cid / 350 th - 70 Chevy Suburban 1/2T 2wd - 454 cid /400 th - 96 Chevy Impala SS - mainly stock - 98 Chevy Tahoe LT 4x4 - all stock The Bad: - 86 Chevy Suburban 1/2T 4x4 - winter beater The Ugly: - 72 Chevy Suburban 1/2T 2wd - parts truck

10-11-2009, 10:47 PM	#9
John H. Registered User Join Date: Oct 2007 Location: Sammamish, WA Posts: 2,115	Re: HEI dist in 4x4 72 Jimmy/Blazer Thanks everyone for the responses. I just ordered new wiring harnesses for the HEi and for an in ternal voltage regulator alternator. I will start a build thread soon.

10-12-2009, 12:55 PM	#10
RckyMntnKng Registered User Join Date: Apr 2007 Location: Meridian, Idaho Posts: 316	Re: HEI dist in 4x4 72 Jimmy/Blazer Sorry not meaning to hi-jack.... On the topic of HEI conversion, what do you need to do with the plug gap if anything? __________________ 71 Jimmy: D60/14BFF, 9"F/11"B Lift, 350-350-203-205, Crossover Hydro steering, Beadlocks, Tube stuff and the bottomless cooler

10-12-2009, 01:06 PM	#12
RckyMntnKng Registered User Join Date: Apr 2007 Location: Meridian, Idaho Posts: 316	Re: HEI dist in 4x4 72 Jimmy/Blazer Thank you. Considering you would just buy all new plugs wires and HEI and do them together.... Is there a difference in just getting new stock plugs at .035 and opening them to .045, or find stock set maybe for some other year with the same thread and depth and the gap already at .045? Id love someone to post the AC/Delco part number to look for. Im currently adding a 65000k HEI and 10mm wires...plugs are last item. Is there any tricks to the install for all 3? Never done a points conversion before. I already changed out the ALT for a Internally regulated. Thanks __________________ 71 Jimmy: D60/14BFF, 9"F/11"B Lift, 350-350-203-205, Crossover Hydro steering, Beadlocks, Tube stuff and the bottomless cooler

10-12-2009, 01:20 PM	#13
jaros44sr Senior Member Join Date: May 2006 Location: Philadelphia, Pa. 19454 Posts: 9,768	Re: HEI dist in 4x4 72 Jimmy/Blazer Mine were ordered as '74 corvette wires w/ramshorn manifolds from Accel...stock size wires are 7mm, but 8mm just go into the factory wire holders. I may be reworking the lenght of the wires, just haven't got aroundtoit plugs would depend on how your engine is built and runs...hotter or colder spark, but basically stock __________________ Semper Fi...Uncle Sam, you da man All parts offered to help are free, unless otherwise noted Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training SAFETY FIRST AS usual, off topic They say your mind goes second, can't remember the first Jim Last edited by jaros44sr; 10-12-2009 at 01:23 PM.

10-12-2009, 11:45 PM	#14
truckster Registered User Join Date: Jan 2001 Location: Orem, Utah Posts: 7,985	Re: HEI dist in 4x4 72 Jimmy/Blazer If my memory serves me, the stock plug for the 350 with HEI is a Delco R44TS.

12-12-2009, 02:48 PM	#16
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,038	Re: HEI dist in 4x4 72 Jimmy/Blazer I had one in my 69. It was tight but cleared the firewall by about 1/8 inch. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

12-12-2009, 04:28 PM	#17
Firebirdjones Registered User Join Date: Oct 2009 Location: Prescott, Arizona Posts: 2,396	Re: HEI dist in 4x4 72 Jimmy/Blazer The AC plug R44TS is simply the small 5/8 plug with a taper seat and extended tip. T=taper seat S=extended tip GM started using these plugs in both big block and small block chevrolets in 1971 and work in pretty much anything up through the late 80's with a cast iron head that doesn't require more reach. You can go as cold as 43's which is what I run in a couple of cars, but that heat range is getting harder to find. Seems the 44's are also getting scarce. You can go as high as 46's if you wish. Most parts stores want to sell you the 45's it seems. For stock or nearly stock engines and close to sea level, I'd shoot for the 44's and go from there. As far as the HEI's, they are a cheap alternative to electronic ignition. Very dependable. The downfall is the size for me. I never liked the bulkyness and the amount of crap you have to remove for a simple cap and rotor change. I'm an MSD person myself, used them for 20 years without a hickup. They can be made to look stock as well, if you are into the stealthy stuff. But a good setup is 5 times the price unfortunately.



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12-12-2009, 10:30 PM	#18
swyfor5 Registered User Join Date: May 2007 Location: Marion, Mi. Posts: 2,429	Re: HEI dist in 4x4 72 Jimmy/Blazer Very interesting topic, as I am looking at upgrading on next rebuild. Currently running the point dist, and time for a change! What wiring changes have to be made?

12-12-2009, 10:37 PM	#19
cparman sharp as a marble Join Date: Jan 2007 Location: atlantic beach,florida Posts: 1,082	Re: HEI dist in 4x4 72 Jimmy/Blazer My Blazer had an HEI in it when I bought it. I have a bunch of clearance??? Her is a poor pic of it. I think I can get my hand around it no problem. Oh yea, i used a set of Taylor wires that I cut to length. I ran the front two on both sides under the motor mount. ( like a Corvette with HEI ) I have done this a bunch of times with Rams horn manifolds. Looks good, and makes teh wire set look very neat. Attached Images Last edited by cparman; 12-12-2009 at 10:48 PM.

12-12-2009, 10:42 PM	#20
pound41 Registered User Join Date: Dec 2002 Location: Northern Virginia Posts: 1,268	Re: HEI dist in 4x4 72 Jimmy/Blazer mallory unilite is about same size as stock and uses the OE style wires

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