Question for big block owners - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**pdr510** · 12-08-2008, 08:40 PM

First question is did the factory big block trucks come with the large hump cabs? Does anyone here have a big block with the short hump floor?

teeitup · 12-08-2008, 08:50 PM

I've parted out 2 trucks that were big blocks turbo 400's that were low humps, the cab looked original and all. But I cannot say for certain they were original.

1968SWBBigBlock · 12-08-2008, 10:16 PM

I have heard it both ways - I am unsure what is correct - mine is a low hump big block truck -

kelsfine69 · 12-08-2008, 10:29 PM

I have a small block truck low hump and put a big block in it with no issues

468BIGBLOCK · 12-08-2008, 10:51 PM

i saw a 402 bb with small hump it was a 3 speed on column

71 super · 12-08-2008, 10:56 PM

I have seen both ways, a 69 396 bucket seat truck with documentation that was a low hump truck, lwb
402/400 truck w bench seat low hump lwb
My 71 swb 402 buckets w high hump
I think that all swb bucket seat truck w/bb were all high hump trucks as were the four speed trucks. Don't know about three speed trucks but would think that would be a rare bird anyway.

**too much stuff** · 12-08-2008, 11:11 PM

My 69 has a high hump(TH400), the 72 i sold with a 3 speed manual had a low hump. I parted a 70 with an auto that was a high hump. Hope this helps.

Longhorn Man · 12-08-2008, 11:14 PM

BB with an auto was supposed to be high hump, but a few slipped through the cracks

caminokid · 12-08-2008, 11:16 PM

Mine has a 396 with a manual. It has the high hump. I also have a 6 cyl with the 4 speed and it has the high hump. I believe it has something to do with the trans not the motor.

**too much stuff** · 12-08-2008, 11:17 PM

Pretty sure every 4 speed truck had a high hump...

BHRS · 12-08-2008, 11:21 PM

My '72 is original with 402/TH400 with the high hump. Had a 70 307/4-speed also had a high hump.

**schwoch1** · 12-08-2008, 11:47 PM

My '71 GMC which came with a 402 and a TH400 has the high hump floor!
Hope this helps!

Mike

Longhorn Man · 12-09-2008, 12:19 AM

ok, we are getting off track.
All 4X4 trucks, and all 4 speeds had the high hump.
On paper, all big blocks had the high hump, however, on the small handfull if big block/3speed manuals that have been found, all have low hump. With that being said, MOST big block/TH400's had the high hump like they awere supposed to have.

Some odd things happened back then... I had a !/2 ton 2 wheel drive 305 V-6/th400 with the high hump... but no one else has seen one like it, they all had low humps.

**pdr510** · 12-09-2008, 08:10 AM

Quote:

Originally Posted by Longhorn Man

ok, we are getting off track.
All 4X4 trucks, and all 4 speeds had the high hump.
On paper, all big blocks had the high hump, however, on the small handfull if big block/3speed manuals that have been found, all have low hump. With that being said, MOST big block/TH400's had the high hump like they awere supposed to have.

Some odd things happened back then... I had a !/2 ton 2 wheel drive 305 V-6/th400 with the high hump... but no one else has seen one like it, they all had low humps.

That is what I was thinking, but was not sure. How much clearance does a big block and 400 have on the low humps? The reason I am asking I just bought a 454 and going to put a 700R4 behind it. Had a small block with overdrive tranny on the 6 cylinder mounts and it was tight.

teeitup · 12-09-2008, 09:21 AM

The 2 that I parted that were low humps, there wasn't very much clearance it seemed, very tight. All the other BB trucks I've ever parted all had high humps. Just a very few had low lumps.

1956cameo · 12-09-2008, 09:33 AM

My 72 suburban came from the factory with a 402 engine and turbo 400 trans and is a High Hump. I have a non original 396 engine with a turbo 400 trans in a 70 chevy truck with low hump and it fits. So in short they will fit into both but were designed to be with high hump.

Tx Firefighter · 12-09-2008, 09:46 AM

Quote:

Originally Posted by pdr510

... How much clearance does a big block and 400 have on the low humps? .....

I have built two big block trucks in the past out of low hump cab trucks. I used correct big block mounts and positioning.

On both of them, the cab hit the trans with the original cab mounts. When I replaced the cab mounts with new fresh ones, they cleared comfortably.

While they work with low cabs fine, there is a reason the factory used tall hump cabs. There's not much room to spare otherwise.

DirtyLarry · 12-09-2008, 10:39 AM

I have had two factory big block 2wd's and both had high humps. Also had two original 2wd small block trucks that both had low humps.

12-08-2008, 08:40 PM	#1
pdr510 Junior Member Join Date: Oct 2005 Location: LA Posts: 158	Question for big block owners First question is did the factory big block trucks come with the large hump cabs? Does anyone here have a big block with the short hump floor? __________________ 1970 C-10 Fleet Side Gen IV 6.0 with 4L80E

12-08-2008, 08:50 PM	#2
teeitup Just like to part out trucks!! Join Date: Nov 2001 Location: Meriden, Ks-North of Topeka 10 miles Posts: 27,396	Re: Question for big block owners I've parted out 2 trucks that were big blocks turbo 400's that were low humps, the cab looked original and all. But I cannot say for certain they were original. __________________ 67 Chev swb stepside 4x4 283 4 speed SOLD 72 blazer 4x4 4 speed Cheyenne 72 GMC swb 4x4 fleet 4 speed, original paint 1958 Cameo (one of 1405 built, it was my dads) 2020 chevy Apex 4x4 crew cab 1969 Z28 with the 302 1980 chevy swb 4x4 1964 chevell Malibu SS 1976 K20, sold new originally out of my dads chevy dealership Members that I've met, over 200 probably closer to 300 in the 12 years I've been on this site, everyone I met "It was a pleasure"

12-08-2008, 10:16 PM	#3
1968SWBBigBlock Active Member Join Date: Oct 2006 Location: Ohio Posts: 1,643	Re: Question for big block owners I have heard it both ways - I am unsure what is correct - mine is a low hump big block truck - __________________ 1968 SWB 454 + .040, 490HP x 540 FT pounds of Torque 10-1 Kb Forged pistons, recon rods w/ ARP wave loc bolts 781 heads Ported with 2.19/1.88 SSTvalves Lunati 60204 cam, Micro Trol lifters, Ported Edelbrock Performer Rpm manifold armor coated, Pertronix Triple Strike Ignition Holley 770 Street Avenger carb,Headers armor coated Built by Watson Ruppel Performance in Sarahsville Ohio. Hardshift Tranny Built Turbo 350,TSI 10" 3000 stall 12 Bolt Eaton Posi 4.10 Richmond Gears moser axles 18.5" x 31" Hoosier Pro Street Radials ET Classic 5 Wheels - polished Power Steering, Power Brakes,Disc Brakes,Tach & Gauge Dash, Tilt,Factory Air (gone) Custom Paint & Body Work Special thanks to my wife, my son and my money tree

12-08-2008, 10:29 PM	#4
kelsfine69 18 Till I Die Join Date: Mar 2005 Location: Alberta, Canada Posts: 1,522	Re: Question for big block owners I have a small block truck low hump and put a big block in it with no issues __________________ 2011 GMC Acadia 1969 GMC BBC LS7 2007 GMC Crew Duramax 1987 Camaro Iroc 350 Tuned Port Injection 42000Km 1987 Chevrolet Silverado 350 TBI 1987 Chevrolet Silverado 350 TBI(yes 2) Take me drunk, I'm too home...

12-08-2008, 10:51 PM	#5
468BIGBLOCK MEMBER OF THE JUNK MAN CLUB Join Date: Jul 2001 Location: paragould arkansas 72450 Posts: 425	Re: Question for big block owners i saw a 402 bb with small hump it was a 3 speed on column __________________ I LIKE 67-72 CHEVYS, I HAVE OWNED OVER 150 OF THEM IN THE LAST 25 YEARS..

12-08-2008, 10:56 PM	#6
71 super Registered User Join Date: Sep 2005 Location: Canton North carolina Posts: 3,080	Re: Question for big block owners I have seen both ways, a 69 396 bucket seat truck with documentation that was a low hump truck, lwb 402/400 truck w bench seat low hump lwb My 71 swb 402 buckets w high hump I think that all swb bucket seat truck w/bb were all high hump trucks as were the four speed trucks. Don't know about three speed trucks but would think that would be a rare bird anyway. __________________ 67 blue step side- bb 68 gold and white swb cst anniversary 68 custom swb hot rod Ls swap 69 swb cst 6 cylinder/ overdrive 69 black/black cst bb swb 70 orange and white cst Canada built truck swb bb 71 black and white super swb bb 71 red and white super swb 72 green and white super swb 4x4 62 nova wagon 400 series Ls swapped 68 Camaro 327/4 speed- 1 owner, original paint 66 Volkswagen bettle 69 auto stick Volkswagen Beetle

12-08-2008, 11:11 PM	#7
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,769	Re: Question for big block owners My 69 has a high hump(TH400), the 72 i sold with a 3 speed manual had a low hump. I parted a 70 with an auto that was a high hump. Hope this helps. __________________ 67 gmc custom lwb dakota truck. Sold...And bought back 69 swb 4x4 project (in progress) 70 c-10 lwb texas truck 70 4x4/BB/bkts/posi/tach(retired) 70 swb (wifes) 70 jimmy camper 71 K-5 factory 2wd 71 cheyenne 4x4/tach/posi/ plow rig 71 Cheyenne20 BB, buckets, tach, tilt, 4 speed 72 jimmy CST wyoming rig 72 jimmy Colorado rig 72 lifted texas 4x4 3/4 ton burb 65 fury conv. 383/auto 65 chrysler 300 "L" 413 auto

12-08-2008, 11:14 PM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Question for big block owners BB with an auto was supposed to be high hump, but a few slipped through the cracks

12-08-2008, 11:16 PM	#9
caminokid Chevy nut Join Date: Jun 2007 Location: Springfield, Illinois Posts: 2,266	Re: Question for big block owners Mine has a 396 with a manual. It has the high hump. I also have a 6 cyl with the 4 speed and it has the high hump. I believe it has something to do with the trans not the motor. __________________ 84 Chevy Custom Deluxe 1/2 Ton Named Fade To Black II "Remember kids there is NO replacement for displacement!"

12-08-2008, 11:17 PM	#10
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,769	Re: Question for big block owners Pretty sure every 4 speed truck had a high hump... __________________ 67 gmc custom lwb dakota truck. Sold...And bought back 69 swb 4x4 project (in progress) 70 c-10 lwb texas truck 70 4x4/BB/bkts/posi/tach(retired) 70 swb (wifes) 70 jimmy camper 71 K-5 factory 2wd 71 cheyenne 4x4/tach/posi/ plow rig 71 Cheyenne20 BB, buckets, tach, tilt, 4 speed 72 jimmy CST wyoming rig 72 jimmy Colorado rig 72 lifted texas 4x4 3/4 ton burb 65 fury conv. 383/auto 65 chrysler 300 "L" 413 auto

12-08-2008, 11:21 PM	#11
BHRS Registered User Join Date: Sep 2007 Location: Wylie TEXAS Posts: 81	Re: Question for big block owners My '72 is original with 402/TH400 with the high hump. Had a 70 307/4-speed also had a high hump. __________________ 1972 Cheyenne C10 Unrestored Original-3 Owner-RUST FREE Texas Truck Big Block-TH400-PS-PB-AC-AM/FM Radio

12-08-2008, 11:47 PM	#12
schwoch1 Local Detroit diesel nut! Join Date: Apr 2008 Location: Burlington, WI Posts: 175	Re: Question for big block owners My '71 GMC which came with a 402 and a TH400 has the high hump floor! Hope this helps! Mike __________________ Nothing cool anymore, I am old and boring....

12-09-2008, 12:19 AM	#13
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Question for big block owners ok, we are getting off track. All 4X4 trucks, and all 4 speeds had the high hump. On paper, all big blocks had the high hump, however, on the small handfull if big block/3speed manuals that have been found, all have low hump. With that being said, MOST big block/TH400's had the high hump like they awere supposed to have. Some odd things happened back then... I had a !/2 ton 2 wheel drive 305 V-6/th400 with the high hump... but no one else has seen one like it, they all had low humps.

12-09-2008, 09:21 AM	#15
teeitup Just like to part out trucks!! Join Date: Nov 2001 Location: Meriden, Ks-North of Topeka 10 miles Posts: 27,396	Re: Question for big block owners The 2 that I parted that were low humps, there wasn't very much clearance it seemed, very tight. All the other BB trucks I've ever parted all had high humps. Just a very few had low lumps. __________________ 67 Chev swb stepside 4x4 283 4 speed SOLD 72 blazer 4x4 4 speed Cheyenne 72 GMC swb 4x4 fleet 4 speed, original paint 1958 Cameo (one of 1405 built, it was my dads) 2020 chevy Apex 4x4 crew cab 1969 Z28 with the 302 1980 chevy swb 4x4 1964 chevell Malibu SS 1976 K20, sold new originally out of my dads chevy dealership Members that I've met, over 200 probably closer to 300 in the 12 years I've been on this site, everyone I met "It was a pleasure"

12-09-2008, 09:33 AM	#16
1956cameo Registered User Join Date: Apr 2008 Location: Angleton, TX Posts: 2,219	Re: Question for big block owners My 72 suburban came from the factory with a 402 engine and turbo 400 trans and is a High Hump. I have a non original 396 engine with a turbo 400 trans in a 70 chevy truck with low hump and it fits. So in short they will fit into both but were designed to be with high hump. Last edited by 1956cameo; 12-09-2008 at 09:34 AM.



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12-09-2008, 10:39 AM	#18
DirtyLarry Windy Corner of a Dirty Street Join Date: Jun 2003 Location: Pueblo West, Colorado Posts: 2,926	Re: Question for big block owners I have had two factory big block 2wd's and both had high humps. Also had two original 2wd small block trucks that both had low humps. __________________ Current vehicle collection: 1978 Chevrolet K10, 8.1L, NV4500, NP205 1989 Chevrolet Suburban, 8.1L, NV4500, NP241 1993 Chevrolet C1500 Sportside, TBI 7.4L, 4L60E 2001 Chevrolet K2500HD, Ext Cab, SWB, 8.1L, ZF 6 speed 2014 Chevrolet Impala LTZ 3.6L Vortec 8.1L because life is too short to tolerate underpowered vehicles Instagram

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