Need some HEI Help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jimmi · 03-25-2007, 09:57 AM

Howdy all, Working on my uncles 71 3/4 ton with a 402. I am trying to talk him in to buying an HEI. I am tired of adjusting points and dwell lol. I wondering if the big HEI CAP IN COIL will fit fire wall clearance? I know on my Chevelle I have the external coil. I can't seem to find them for sale. If the big cap will fit I will just co with that. Jim

3/4tonterror · 03-25-2007, 10:12 AM

Yes it will fit with plenyt of clerance. I have HEI in my 2wd and 4wd, plenty of room.But less room in my 4wd.

Jimmi · 03-25-2007, 10:43 AM

Thanks for the advise! Jim

cdowns · 03-25-2007, 11:42 AM

if he wants to retain the original look/ pertronix makes a really nice billet hei that uses original size and type of cap and uses an external coil/not cheap at over $200 for the setup

Bill72BB · 03-26-2007, 01:02 PM

I have that setup no problem , Here are the spec some of us used to set up the HEI.
When I installed an H.E.I unit in my ( 402 engine) ; I had a distributor rebuild shop set the advance curves as per the GM factory manual. The specs are :- 0 degrees @ 930 RPM; 2 @ 1260 RPM; 16 @ 2400 RPM and 30 @ 4400 RPM. Vacuum advance specs are 0 degrees @ 8" hg and 20 degrees @ 17" h.g. Initial ignition timing is 8 degrees advance @ 600 RPM ( idle speed).
... Above specs are from GM 1971 Chevrolet Truck Service Manual.
... Another GM reference is the 'GM/AC/Delco Tune-up Specs Manual # SD-100. These specs call for a 10-13 degree centrifugal advance @ 2000 RPM and a total advance ( vacuum & centrifugal ) of 28 to 35 @ 2000 RPM...... When I installed my unit about 10 years ago; I used an adjustable timing lite and set the timing to 35 degrees @ 2000.........No problems and I am well satisfied with the engine performance.............

mnunn454 · 03-26-2007, 08:43 PM

Large cap HEI fits in my 69 with a BBC.

One point though (no pun intended). The power wire to a points distrib is usually a resister wire that reduces voltage to keep from burning up the points. HEI needs a full 12 volts, so suggest you loose the resister wire if it's there.

Snew · 03-26-2007, 09:32 PM

I did the same swap. I got my wire from Year one. It snapped right into the back of the fuse block and had the correct connector for the distributor on the other end. Really felt like a good job to me.

Bill72BB · 03-27-2007, 12:50 AM

Just wanted to mention that the setup figures I posted were from GMC JIM ,one of the few members on this board older than me .

timcos · 03-27-2007, 01:02 AM

I did shave off thew rear 1/4 inch of my HEI cap...nothing but plastic shaping and fins.

03-25-2007, 09:57 AM	#1
Jimmi Registered User Join Date: Mar 2007 Location: Arizona Posts: 13	Need some HEI Help Howdy all, Working on my uncles 71 3/4 ton with a 402. I am trying to talk him in to buying an HEI. I am tired of adjusting points and dwell lol. I wondering if the big HEI CAP IN COIL will fit fire wall clearance? I know on my Chevelle I have the external coil. I can't seem to find them for sale. If the big cap will fit I will just co with that. Jim

03-25-2007, 10:12 AM	#2
3/4tonterror Registered User Join Date: Dec 2006 Location: jaffrey,NH Posts: 325	Re: Need some HEI Help Yes it will fit with plenyt of clerance. I have HEI in my 2wd and 4wd, plenty of room.But less room in my 4wd.

03-25-2007, 10:43 AM	#3
Jimmi Registered User Join Date: Mar 2007 Location: Arizona Posts: 13	Re: Need some HEI Help Thanks for the advise! Jim

03-25-2007, 11:42 AM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Need some HEI Help if he wants to retain the original look/ pertronix makes a really nice billet hei that uses original size and type of cap and uses an external coil/not cheap at over $200 for the setup __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

03-26-2007, 01:02 PM	#5
Bill72BB Thats the Hillbilly way Join Date: Jul 2001 Location: Torrance,Ca Posts: 5,980	Re: Need some HEI Help I have that setup no problem , Here are the spec some of us used to set up the HEI. When I installed an H.E.I unit in my ( 402 engine) ; I had a distributor rebuild shop set the advance curves as per the GM factory manual. The specs are :- 0 degrees @ 930 RPM; 2 @ 1260 RPM; 16 @ 2400 RPM and 30 @ 4400 RPM. Vacuum advance specs are 0 degrees @ 8" hg and 20 degrees @ 17" h.g. Initial ignition timing is 8 degrees advance @ 600 RPM ( idle speed). ... Above specs are from GM 1971 Chevrolet Truck Service Manual. ... Another GM reference is the 'GM/AC/Delco Tune-up Specs Manual # SD-100. These specs call for a 10-13 degree centrifugal advance @ 2000 RPM and a total advance ( vacuum & centrifugal ) of 28 to 35 @ 2000 RPM...... When I installed my unit about 10 years ago; I used an adjustable timing lite and set the timing to 35 degrees @ 2000.........No problems and I am well satisfied with the engine performance............. __________________ BILL Torrance Calif 90504 Member DUF Club Member Old Farts Club 72 3/4ton Custom Camper BB402/400 trans Dynomax Cerama-coat headers , Hei distributor ,Edelbrock 1411 air,ps,pb,leafsprings ,98 chevy 60/40 seat,S10 shoulder belts tilt,3.54 Dana 60 rear. 16" Eagle wheels with LT265/75 16 tires,Gaylord Lid,H4 headlights with 100W relay conversion. " If I knew I was going to live this long I would have taken better care of myself " Marriage changes passion...suddenly you're in bed with a relative. A GUY'S PRAYER.... Lord, I pray for a nympho with huge boobs who owns a liquor store and likes to fish and hunt and has a Harley .Amen ,

03-26-2007, 08:43 PM	#6
mnunn454 Registered User Join Date: Dec 2006 Location: Rhode Island Posts: 602	Re: Need some HEI Help Large cap HEI fits in my 69 with a BBC. One point though (no pun intended). The power wire to a points distrib is usually a resister wire that reduces voltage to keep from burning up the points. HEI needs a full 12 volts, so suggest you loose the resister wire if it's there. __________________ 69 C-10 SWB Fleetside 454/TH400 (For Sale) http://67-72chevytrucks.com/vboard/c...ct=1299&cat=12 70 El Camino 454 TH700 29 Model A 4-DR Sedan Deluxe

03-26-2007, 09:32 PM	#7
Snew Registered User Join Date: Jun 2006 Location: Hillsboro, OR Posts: 28	Re: Need some HEI Help I did the same swap. I got my wire from Year one. It snapped right into the back of the fuse block and had the correct connector for the distributor on the other end. Really felt like a good job to me.

03-27-2007, 12:50 AM	#8
Bill72BB Thats the Hillbilly way Join Date: Jul 2001 Location: Torrance,Ca Posts: 5,980	Re: Need some HEI Help Just wanted to mention that the setup figures I posted were from GMC JIM ,one of the few members on this board older than me . __________________ BILL Torrance Calif 90504 Member DUF Club Member Old Farts Club 72 3/4ton Custom Camper BB402/400 trans Dynomax Cerama-coat headers , Hei distributor ,Edelbrock 1411 air,ps,pb,leafsprings ,98 chevy 60/40 seat,S10 shoulder belts tilt,3.54 Dana 60 rear. 16" Eagle wheels with LT265/75 16 tires,Gaylord Lid,H4 headlights with 100W relay conversion. " If I knew I was going to live this long I would have taken better care of myself " Marriage changes passion...suddenly you're in bed with a relative. A GUY'S PRAYER.... Lord, I pray for a nympho with huge boobs who owns a liquor store and likes to fish and hunt and has a Harley .Amen , Last edited by Bill72BB; 03-27-2007 at 12:51 AM.

03-27-2007, 01:02 AM	#9
timcos Chief Honcho In Charge Join Date: Aug 2006 Location: Bentonville AR Posts: 970	Re: Need some HEI Help I did shave off thew rear 1/4 inch of my HEI cap...nothing but plastic shaping and fins. __________________ 1992 1500 4x4 Shortbed 1984 Ford F250 Supercab Longbed 6.9L Diesel 1972 K10 Cheyenne Super Fleetside Short Bed - 350 - A/C 1971 VW SuperBeetle 1960 Wife 1984 Son 1986 Son 1989 Son Previous Trucks 1967 C10 SWB (1980-1981) 1971 C10 LWB (1998-2004)



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