Fire wall differances.... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Longhorn Man · 08-25-2002, 04:55 PM

I just noticed something interesting, maybe someone can tell me why it's like this.
I have 3 cabs all together.
1 GMC 1/2 ton '69. (mounted)
1 Chevy 1 ton '70. (mounted)
1 Chevy 3/4 ton '70 (not mounted)
While I have no pics of the 3/4 ton cab on hand showing this, I just looked at it yesterday, and it is just like the one ton, but the GMC is differant.
The clutch hole on the firewall on the one ton and the 3/4 ton, are both like this one, where it is exiting above the bend that starts the floor.

But the GMC has it like this...

Longhorn Man · 08-25-2002, 04:56 PM

Maybe some one can tell me by looking at there fleet...
is it becouse the year?
is it becouse GMC vrs Chevy?
is it 1/2 ton verses 3/4 ton and one ton????

**ThreeQuarter** · 08-25-2002, 05:02 PM

Interesting...I wish I had a pic of the '72 GMC 3/4 cab. I think it was on the angle section (lower hole, second pic). Does that mean it's a GMC thinng? I would doubt it, since Chevys and GMCs were made on the same lines. But maybe it mattered what line they came off of?

I'm curious to see an explanation of this.

*Gee_Emm* · 08-25-2002, 06:27 PM

Its not like that on any of the 3 cabs I have here, 2 of them 1/2 tons, 1 of them 3/4 ton, none of them GMC's

That just looks wierd, I don't think I have seen any like that before.

Longhorn Man · 08-25-2002, 06:59 PM

Interesting...
I started thinking about how the 1/2 ton is the only one with oddball cab mounts out of the whole C/10 - C/30 (including the K trucks). But then i thought that the 1/2 ton would have it up high, like my other 2 since the 1/2 ton sits lower onto the frame...
still making no sence.
This GMC has a few oddities about it.
No one has confirmed that a 2 wheel drive 305 V-6 with a TH400 should have a high hump ...but it does.
Also, in that hump, some of you will remember, it has some sort of hole down at the bottom of the hump...again...factory.

Southpa · 08-25-2002, 07:19 PM

I can either perplex you more or make things simpler, depends on how you look at it. I went out and had a look for myself, like a few others I'll bet. I have a 1970 GMC 1/2 ton, clutch hole is like the first pic you posted, above the bend and its a large oval.

So the hole below the bend is not unique to 1/2 tons, but still could be a difference in year and/or Chevy/GMC.

Hooter · 08-25-2002, 07:26 PM

My renter had a 1 ton 69 GMC cab with the clutch hole like in your second picture, weird never really thought much about till this post

wbmoore · 08-25-2002, 10:33 PM

I too had a GMC with the lower hole........I thought it was because it was a V6. Sounds like it is a GMC thing. Mine was a '67.

**ThreeQuarter** · 08-25-2002, 11:11 PM

Hey Andy, don't all TH400s have high humps? My '67 C20 327/TH400 does.

**breeh** · 08-25-2002, 11:33 PM

My GMC is like first pic...

Blue_71 · 08-25-2002, 11:41 PM

my 70 cab, and both 71s have it like the longhorn.. id have to check on the 72, never payed attention to it

Longhorn Man · 08-25-2002, 11:50 PM

Not all TH400 trucks had the high hump, the one ton longhorn has a low hump and came with the TH400.
It is said that only 4X4's and big block trucks...but I think the V-6 trucks did too regerdles of tranny...just no one is able to confirm it.

Hooter · 08-26-2002, 01:43 AM

My 69 chev has orignal th 400 with low hump

OhioDan · 08-26-2002, 05:36 AM

My 70 GMC 3/4 ton, looks like the first pic.

Longhorn Man · 08-26-2002, 06:41 PM

Interesting...at a glance, I see no trend here. Anyone else before I tally up the facts here?

*Gee_Emm* · 08-26-2002, 07:08 PM

Put me down for a low hump 400 and regular holes on 3/4ton and 1/2 ton Chevs

Longhorn Man · 08-26-2002, 07:26 PM

lol gee-emm...which you calling a regular hole...the first pic or the second one?

Mountain Man · 08-26-2002, 10:48 PM

I see a bit of a trend here. It could be a 69 GMC thing, or it could be a V6 thing. I am not home right now (in hotel room, on laptop), so I can't check my 67 GMC

*Gee_Emm* · 08-26-2002, 11:49 PM

Define Normal,

Im not the one with the freak truck here :P

Longhorn Man · 08-27-2002, 12:31 AM

Quote:

Originaly said by Austin Powers Ouch man...Very ouch...

She's not a freak...she's Special

08-25-2002, 04:55 PM	#1
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Fire wall differances.... I just noticed something interesting, maybe someone can tell me why it's like this. I have 3 cabs all together. 1 GMC 1/2 ton '69. (mounted) 1 Chevy 1 ton '70. (mounted) 1 Chevy 3/4 ton '70 (not mounted) While I have no pics of the 3/4 ton cab on hand showing this, I just looked at it yesterday, and it is just like the one ton, but the GMC is differant. The clutch hole on the firewall on the one ton and the 3/4 ton, are both like this one, where it is exiting above the bend that starts the floor. But the GMC has it like this... Attached Images

08-25-2002, 05:02 PM	#3
ThreeQuarter Senior Member Join Date: Jun 2000 Location: Texan in Iowa Posts: 2,522	Interesting...I wish I had a pic of the '72 GMC 3/4 cab. I think it was on the angle section (lower hole, second pic). Does that mean it's a GMC thinng? I would doubt it, since Chevys and GMCs were made on the same lines. But maybe it mattered what line they came off of? I'm curious to see an explanation of this. __________________ Ben '68 Chevy C10 Custom LWB 327/TH400 2nd owner '16 GMC Sierra 1500 SLE Dblcab 4wd 5.3

08-25-2002, 07:19 PM	#6
Southpa Registered User Join Date: May 2000 Location: Victoria, BC, Canada Posts: 2,410	I can either perplex you more or make things simpler, depends on how you look at it. I went out and had a look for myself, like a few others I'll bet. I have a 1970 GMC 1/2 ton, clutch hole is like the first pic you posted, above the bend and its a large oval. So the hole below the bend is not unique to 1/2 tons, but still could be a difference in year and/or Chevy/GMC. __________________ 1970 GMC 1500 Custom Original 350/TH350 Victoria, BC, Canada You can wish in one hand and crap in the other. See which one gets filled first.

08-25-2002, 07:26 PM	#7
Hooter My other Love Join Date: Aug 2001 Location: Castlegar B.C. Canada Posts: 4,085	My renter had a 1 ton 69 GMC cab with the clutch hole like in your second picture, weird never really thought much about till this post __________________ Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life

08-25-2002, 10:33 PM	#8
wbmoore Registered User Join Date: Jul 2001 Location: Big Bar, California Posts: 136	67 GMC "lower hole" I too had a GMC with the lower hole........I thought it was because it was a V6. Sounds like it is a GMC thing. Mine was a '67.

08-25-2002, 04:56 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Maybe some one can tell me by looking at there fleet... is it becouse the year? is it becouse GMC vrs Chevy? is it 1/2 ton verses 3/4 ton and one ton????

08-25-2002, 06:27 PM	#4
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 4,002	Its not like that on any of the 3 cabs I have here, 2 of them 1/2 tons, 1 of them 3/4 ton, none of them GMC's That just looks wierd, I don't think I have seen any like that before.

08-25-2002, 06:59 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Interesting... I started thinking about how the 1/2 ton is the only one with oddball cab mounts out of the whole C/10 - C/30 (including the K trucks). But then i thought that the 1/2 ton would have it up high, like my other 2 since the 1/2 ton sits lower onto the frame... still making no sence. This GMC has a few oddities about it. No one has confirmed that a 2 wheel drive 305 V-6 with a TH400 should have a high hump ...but it does. Also, in that hump, some of you will remember, it has some sort of hole down at the bottom of the hump...again...factory.

08-25-2002, 11:11 PM	#9
ThreeQuarter Senior Member Join Date: Jun 2000 Location: Texan in Iowa Posts: 2,522	Hey Andy, don't all TH400s have high humps? My '67 C20 327/TH400 does. __________________ Ben '68 Chevy C10 Custom LWB 327/TH400 2nd owner '16 GMC Sierra 1500 SLE Dblcab 4wd 5.3

08-25-2002, 11:33 PM	#10
breeh Recovering 67-72 Addict Join Date: Oct 2000 Location: North Bend, WA Posts: 1,788	My GMC is like first pic... __________________ 68 Short Fleet 4x4; 427; BTO Level 3 700R4; NP205; Dana 60 front and rear; 4" lift with 35's; Disc brakes; AGR variable ratio steering; factory bucket seats; factory tach and tilt. "Friends call me cruzer cuz I like fast cars and fast women"

08-25-2002, 11:50 PM	#12
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Not all TH400 trucks had the high hump, the one ton longhorn has a low hump and came with the TH400. It is said that only 4X4's and big block trucks...but I think the V-6 trucks did too regerdles of tranny...just no one is able to confirm it.

08-26-2002, 01:43 AM	#13
Hooter My other Love Join Date: Aug 2001 Location: Castlegar B.C. Canada Posts: 4,085	My 69 chev has orignal th 400 with low hump __________________ Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life

08-26-2002, 05:36 AM	#14
OhioDan Registered User Join Date: Apr 2002 Location: New Carlisle, Ohio,USA Posts: 1,404	My 70 GMC 3/4 ton, looks like the first pic. __________________ LIFE AIN'T EASY WHEN YER FAT AND GREASY! GMC= Got More Class! 1970 GMC LWB, Fleetside, 350/4spd, Flowmaster "40's", 2002 GMC 16" Rallies, cowl hood,and added a bunch of options that weren't there when I started.

08-26-2002, 06:41 PM	#15
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Interesting...at a glance, I see no trend here. Anyone else before I tally up the facts here?

08-26-2002, 07:08 PM	#16
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 4,002	Put me down for a low hump 400 and regular holes on 3/4ton and 1/2 ton Chevs



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08-26-2002, 07:26 PM	#17
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	lol gee-emm...which you calling a regular hole...the first pic or the second one?

08-26-2002, 10:48 PM	#18
Mountain Man Registered User Join Date: Jan 2002 Location: Calgary, Alberta, Canada Posts: 451	I see a bit of a trend here. It could be a 69 GMC thing, or it could be a V6 thing. I am not home right now (in hotel room, on laptop), so I can't check my 67 GMC __________________ 72 C10 Cheyenne Super Full trim Factory tach dash A/C dash Factory tilt 350 / 350 power train - with Edelbrock components.

08-26-2002, 11:49 PM	#19
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 4,002	Define Normal, Im not the one with the freak truck here :P Last edited by Gee_Emm; 08-27-2002 at 12:07 AM.

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