HEI firewall clearance on a big block - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**leddzepp** · 05-19-2010, 01:33 PM

I will be swapping in an HEI unit in my 72 big block. I have heard there may be clearance issues with the cap and firewall. Are there any issues, or is there enough clearance? Will I be able to drop the distributor in after the engine is put back in the truck, or do I need to do it before? Thanks in advance.

crakarjax · 05-19-2010, 01:57 PM

they wouldn't have put big blocks in at the factory if you couldnt take the dizzy out after it was installed... that would just be a terrible decision. I do notice that the firewall clearance is tight with my sbc though, however I'm not sure that big blocks sit any higher than sbcs, I've never measured.

**leddzepp** · 05-19-2010, 02:12 PM

HEI was not put in at the factory on our trucks, this is why I am asking.

budnikguy · 05-19-2010, 02:33 PM

subscribed....about to run into the same problem, that is, if it is a problem?!

don t. - 72gmc · 05-19-2010, 02:47 PM

I put a Skip White HEI dizzy in my 70 GMC w/a BB (396/400/402).
No problems at all.

HTH...don t. .....

FLDBRED · 05-19-2010, 02:52 PM

The HEI would not fit right on my 71 4X4 small block! I don't know if that is usual! It was to close to the fire wall.

basemodel67 · 05-19-2010, 03:08 PM

In 4X4's, the engine sits farther back, that is why there is a clearance problem with HEI hitting firewall.

**leddzepp** · 05-19-2010, 03:24 PM

I have HEI in my 72 2WD small block truck. It fits with no issues. I will be putting one in my other 72 2WD big block truck.

my67chevytruck · 05-19-2010, 03:34 PM

Ledd, I have seen several BBC 67-72 with hei's....

**leddzepp** · 05-19-2010, 03:37 PM

Quote:

Originally Posted by don t. - 72gmc

I put a Skip White HEI dizzy in my 70 GMC w/a BB (396/400/402).
No problems at all.

HTH...don t. .....

Quote:

Originally Posted by my67chevytruck

Ledd, I have seen several BBC 67-72 with hei's....

Thanks guys, this was the info I was looking for

69sixpackbee · 05-19-2010, 03:42 PM

Mine fits swell in my '72 402

rbagley · 05-19-2010, 04:03 PM

Quote:

Originally Posted by 69 1/2 Six Pack Bee

Mine fits swell in my '72 402

Same with mine. The back two screws are a little tricky to get at, but it fits fine.

cdowns · 05-19-2010, 04:18 PM

there's plenty of small cap HEI dizzys on the market if interested in that route

my67chevytruck · 05-19-2010, 04:53 PM

Yeah i forgot to mention that skip white performance carries the small cap dist. as well.

epashhans · 05-19-2010, 07:08 PM

My 67 2wd with a bb and custom made engine mounts was really close. I just "massaged" the firewall a bit and it works. Its pretty close, but it works just fine.

**leddzepp** · 05-19-2010, 07:32 PM

Quote:

Originally Posted by cdowns

there's plenty of small cap HEI dizzys on the market if interested in that route

Quote:

Originally Posted by my67chevytruck

Yeah i forgot to mention that skip white performance carries the small cap dist. as well.

I thought about going that route if there was clearance issues with the large cap HEI. I wanted to eliminate the external coil if it was possible.

Quote:

Originally Posted by epashhans

My 67 2wd with a bb and custom made engine mounts was really close. I just "massaged" the firewall a bit and it works. Its pretty close, but it works just fine.

Mine has the factory mounts in it, so judging from the above responses, I should be OK. It is too late for me to "massage" the firewall...I just got done painting it a few days ago

*67/72junkie* · 05-19-2010, 07:59 PM

no clearance problems with factory bb mounts , clears fire wall by 1/4 in sb with it set back 7'' on reverse 6cyl mounts as far as it can go .if it hits your cab mounts need replacing.

c10seconds · 05-19-2010, 08:14 PM

Ive got aftermarket BB mounts and I am not able to take out my HEI unless I unbolt the motor. I can barely get the driverside valve cover off and on. My motor sits really close to the firewall for some reason

**leddzepp** · 05-19-2010, 08:49 PM

Quote:

Originally Posted by 67/72junkie

no clearance problems with factory bb mounts , clears fire wall by 1/4 in sb with it set back 7'' on reverse 6cyl mounts as far as it can go .if it hits your cab mounts need replacing.

Good point Donald. I replaced all the cab mounts with new rubber, so I should be good to go

This is for my project truck and I am rebuilding/replacing everything so there are no issues down the road. I see you had a successful west coast parts run recently....congrats!

tim21391 · 05-20-2010, 12:09 AM

i got an accel distributor with the coil pack on top of the dist. and i had plenty of room on my 402

petey-pablo · 05-20-2010, 07:08 AM

No clearance problems with 72 factory bb mounts But then again Im useing a MSD Dizzy & the cap is alittle smaller. my tall valve covers come off fine up & forward not straight up.

**Tom Vogel** · 05-20-2010, 08:50 AM

MSD dist and valve covers with stock 72 mounts

petey-pablo · 05-20-2010, 08:56 AM

Quote:

Originally Posted by Tom Vogel

MSD dist and valve covers with stock 72 mounts

WoW thats one nice motor..

05-19-2010, 01:33 PM	#1
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 20,117	HEI firewall clearance on a big block I will be swapping in an HEI unit in my 72 big block. I have heard there may be clearance issues with the cap and firewall. Are there any issues, or is there enough clearance? Will I be able to drop the distributor in after the engine is put back in the truck, or do I need to do it before? Thanks in advance. __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man RIP FleetsidePaul

05-19-2010, 01:57 PM	#2
crakarjax Registered User Join Date: Dec 2009 Location: Kirkland, WA Posts: 1,302	Re: HEI firewall clearance on a big block they wouldn't have put big blocks in at the factory if you couldnt take the dizzy out after it was installed... that would just be a terrible decision. I do notice that the firewall clearance is tight with my sbc though, however I'm not sure that big blocks sit any higher than sbcs, I've never measured. __________________ 1968 LWB C20 / AC / Wood Bed

05-19-2010, 02:12 PM	#3
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 20,117	Re: HEI firewall clearance on a big block HEI was not put in at the factory on our trucks, this is why I am asking. __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man RIP FleetsidePaul

05-19-2010, 02:33 PM	#4
budnikguy Registered User Join Date: Sep 2007 Location: Riverside, CA Posts: 4,316	Re: HEI firewall clearance on a big block subscribed....about to run into the same problem, that is, if it is a problem?!

05-19-2010, 02:47 PM	#5
don t. - 72gmc Registered User Join Date: Dec 2001 Location: harvard, il. USA Posts: 397	Re: HEI firewall clearance on a big block I put a Skip White HEI dizzy in my 70 GMC w/a BB (396/400/402). No problems at all. HTH...don t. .....

05-19-2010, 02:52 PM	#6
FLDBRED Registered User Join Date: Jun 2009 Location: CENTRAL,NJ Posts: 586	Re: HEI firewall clearance on a big block The HEI would not fit right on my 71 4X4 small block! I don't know if that is usual! It was to close to the fire wall.

05-19-2010, 03:08 PM	#7
basemodel67 Factory Strippers Rule! Join Date: Mar 2009 Location: Shingle Springs, CA Posts: 707	Re: HEI firewall clearance on a big block In 4X4's, the engine sits farther back, that is why there is a clearance problem with HEI hitting firewall. __________________ "Feast your eyes on a feast of smoke." 67 Chevy Short Fleet PLAN: LQ9, 4L60, D60 Looking for School Bus Gauges - Help me out!

05-19-2010, 03:24 PM	#8
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 20,117	Re: HEI firewall clearance on a big block I have HEI in my 72 2WD small block truck. It fits with no issues. I will be putting one in my other 72 2WD big block truck. __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man RIP FleetsidePaul

05-19-2010, 03:34 PM	#9
my67chevytruck Under Construction Join Date: Oct 2007 Location: Midlothian,TX (DFW) Posts: 4,555	Re: HEI firewall clearance on a big block Ledd, I have seen several BBC 67-72 with hei's.... __________________ Heath subscribe to the board here: http://67-72chevytrucks.com/vboard/payments.php http://67-72chevytrucks.com/vboard/s...d.php?t=157669 FAQ how to's 1956 Chevy Apache 1967 C10 SWB FleetSide (under construction) 1969 K10 SWB FleetSide (Future Build) 1972 C10 SWB Stepside (Future Build) 56 chevy truck : http://www.cardomain.com/ride/2955823/1 67 truck build: http://www.67-72chevytrucks.com/vboard/showthread.php?t=281357/1 69 k10: http://67-72chevytrucks.com/vboard/s...d.php?t=389470

05-19-2010, 03:42 PM	#11
69sixpackbee Registered User Join Date: Jan 2001 Location: Sabinal, Texas Posts: 1,706	Re: HEI firewall clearance on a big block Mine fits swell in my '72 402

05-19-2010, 04:18 PM	#13
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: HEI firewall clearance on a big block there's plenty of small cap HEI dizzys on the market if interested in that route __________________ 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

05-19-2010, 04:53 PM	#14
my67chevytruck Under Construction Join Date: Oct 2007 Location: Midlothian,TX (DFW) Posts: 4,555	Re: HEI firewall clearance on a big block Yeah i forgot to mention that skip white performance carries the small cap dist. as well. __________________ Heath subscribe to the board here: http://67-72chevytrucks.com/vboard/payments.php http://67-72chevytrucks.com/vboard/s...d.php?t=157669 FAQ how to's 1956 Chevy Apache 1967 C10 SWB FleetSide (under construction) 1969 K10 SWB FleetSide (Future Build) 1972 C10 SWB Stepside (Future Build) 56 chevy truck : http://www.cardomain.com/ride/2955823/1 67 truck build: http://www.67-72chevytrucks.com/vboard/showthread.php?t=281357/1 69 k10: http://67-72chevytrucks.com/vboard/s...d.php?t=389470

05-19-2010, 07:08 PM	#15
epashhans Registered User Join Date: Jul 2009 Location: MT Posts: 319	Re: HEI firewall clearance on a big block My 67 2wd with a bb and custom made engine mounts was really close. I just "massaged" the firewall a bit and it works. Its pretty close, but it works just fine. __________________ '67 C-10 Shorty - 454, 5spd, and speed holes!

05-19-2010, 07:59 PM	#17
67/72junkie Account Suspended Join Date: Oct 2002 Location: NC Posts: 1,129	Re: HEI firewall clearance on a big block no clearance problems with factory bb mounts , clears fire wall by 1/4 in sb with it set back 7'' on reverse 6cyl mounts as far as it can go .if it hits your cab mounts need replacing.

05-19-2010, 08:14 PM	#18
c10seconds Registered User Join Date: Oct 2009 Location: gilbert,AZ Posts: 947	Re: HEI firewall clearance on a big block Ive got aftermarket BB mounts and I am not able to take out my HEI unless I unbolt the motor. I can barely get the driverside valve cover off and on. My motor sits really close to the firewall for some reason



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05-20-2010, 12:09 AM	#20
tim21391 Registered User Join Date: Jul 2007 Location: Salina, Kansas Posts: 1,998	Re: HEI firewall clearance on a big block i got an accel distributor with the coil pack on top of the dist. and i had plenty of room on my 402 __________________ 1972 C-10...402/400..flowmaster 40 series 1967 Mustang 347 stroker/C-4 1966 Mustang 289/3-speed 2013 Mustang V6/6speed w/300 ponies I may be 23, but i sure do knows 67-72s are sexy! Its not MPG its smiles per gallon! build started 11/25/08 build thread: http://67-72chevytrucks.com/vboard/s....php?p=2993796

05-20-2010, 07:08 AM	#21
petey-pablo "THE GREEN GOBLIN" Join Date: Mar 2008 Location: Fremont Ca. Posts: 1,025	Re: HEI firewall clearance on a big block No clearance problems with 72 factory bb mounts But then again Im useing a MSD Dizzy & the cap is alittle smaller. my tall valve covers come off fine up & forward not straight up. __________________ Petey-pablo "THE GREEN GOBLIN" 1972 Cheyenne 10 Short Fleet Side Front 2.5inch Spindles with 2inch Springs Rear 4inch drop Springs. 454BBC TH400,Posi 1971 Cheyenne 10 Long Fleet Side 454BBC TH350,Posi Sold Drive it like you stole it! Petey-pablo@sbcglobal.net

05-20-2010, 08:50 AM	#22
Tom Vogel 2WD Jimmy Join Date: Mar 2005 Location: Davis County, Utah Posts: 2,565	Re: HEI firewall clearance on a big block MSD dist and valve covers with stock 72 mounts Attached Images

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