small hump? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sgtjed · 12-09-2002, 02:14 AM

anyone have any pics of a small hump vs a large hump?

i have a 70 c10 that had a 6cyl three speed on the column. i have since converted it over to a 327/350.
i have heard the term small hump and large hump but havnt paid much attention to the trucks i have owned to really know what i have. reason i am asking is that i plan on getting carpet for my truck after christmas and need to know what to look for to determine between the two humps.
i am betting that i have a small hump due to it had the saginaw three speed in it.

spinning wheels · 12-09-2002, 02:51 AM

From what I have read. The large hump was in 4x4 trucks and also trucks with turbo 400 trannys. I found this out when I was installing rubber floor mat in my 3/4 ton truck. Good luck with this info.

OhioDan · 12-09-2002, 06:29 AM

Check out Wes's website at http://classicheartbeat.com/index.html
Check page 2 under interiors, and there's a tech tip to explain the difference between low hump and high hump. Hope this helps?

Lightspeed · 12-09-2002, 12:11 PM

high humps were used in trucks that were originally 4x4 or originally came with a floor shift transmission. low humps were trucks that had column shift transmission.

sgtjed · 12-09-2002, 04:13 PM

cool thanks guys,i guess i have a low hump then.

Mike C · 12-09-2002, 10:12 PM

MOST big block trucks with autos were high humps as well, but most had TH400s. One exception to this might be 1/2 ton big blocks, especially in Suburbans.

gashog · 12-09-2002, 10:22 PM

Here's a pic of a low hump in my 69 C/10 turbo 400 small block.

Hooter · 12-09-2002, 10:28 PM

Hmm I always thought I had a small hump. Now that I see that pic I guess i have a big hump. I have a th400 in my 69. I always thought the large hump cabs had the center hub that was bolted to the cab?

**Palf70Step** · 12-09-2002, 10:42 PM

I have heard, but never seen one myself, that high humps bolt in, while the low humps, like the picture shows, are integral with the floorboard.

**Classic Heartbeat** · 12-09-2002, 10:57 PM

Here is a link to where I have the explenation in my helpfull tips section of our website. Pictures too!!
http://www.classicheartbeat.com/high_low_humps.htm
WES www.ClassicHeartbeat.com

chevy2racr · 12-09-2002, 11:17 PM

yeah high humps bolt in, lows are part of he floor, lows are something like 3-4 inches tall tops

sgtjed · 12-10-2002, 12:03 AM

well that helped a ton,thanks!! i now know i have a low hump.

Longhorn Man · 12-10-2002, 12:36 AM

It has been documented that 4 speeds, 4X4's, and big block trucks had high humps....but I suspect that GMC trucks with the V-6 had them too. I know mine (with a TH400) has a high hump....however, the one ton that had a 350/TH400 has a small hump.
Here is the high hump bolt in deal in my GMC.

gangforward · 12-10-2002, 12:44 AM

If you have a low hump - (327 motor, glide) and are going to convert to a Big Block and Turbo 400, do you have to go to the high hump, or will it fit with the lowhump?

Longhorn Man · 12-11-2002, 12:28 AM

most likely....they did at the factory.

bodad · 12-11-2002, 04:40 AM

So, is the low hump welded to the floor. I have a project going that has a HH now but it originally was a LH. The HH has a cutout for what looks like a 4 sp. and I will need to patch it to cover the hole. It is back with the 350/350 setup so I no longer need the HH. Instead of patching the HH would I be able to weld in a LH if I can find one?

chevy2racr · 12-11-2002, 04:31 PM

if you find one outta a junked truck you can weld it back in yes

imdarren · 12-11-2002, 09:14 PM

So can someone confirm.....
You can fit a big block with a TH 400 in a pickup that has a small hump? No clearance problems?
Longhornmail may have answered this. But it was unclear whos question he was answering.

Thanks, Darren

Dropt72Shortbed · 12-11-2002, 09:41 PM

can a high hump cab be converted to a low hump relatively easy? i prefer the low hump better but the new cab im purchasing is a high hump

can a low hump section be purchased from anywhere or would i have to go cut one out a junk yard cab?

Longhorn Man · 12-12-2002, 12:30 AM

darren, I was refering to your Q...but it is mostly speculation.
I know it is starting to look like I'll have hump clearnace trouble on my caddy swap...but that don't really cound.

MOTHERTRUCKERS · 12-12-2002, 09:41 AM

We have put big blocks and t-400's in low humps without any real problems, on one we had to cut the firewall to floor seam flush in the hump and weld it back together, could have just hammered it flat and it would have worked.

12-09-2002, 02:14 AM	#1
sgtjed What if? Join Date: Oct 2002 Location: Choctaw,Oklahoma Posts: 649	small hump? anyone have any pics of a small hump vs a large hump? i have a 70 c10 that had a 6cyl three speed on the column. i have since converted it over to a 327/350. i have heard the term small hump and large hump but havnt paid much attention to the trucks i have owned to really know what i have. reason i am asking is that i plan on getting carpet for my truck after christmas and need to know what to look for to determine between the two humps. i am betting that i have a small hump due to it had the saginaw three speed in it.

12-09-2002, 02:51 AM	#2
spinning wheels Registered User Join Date: Sep 2001 Location: Hacienda Heights, California USA Posts: 474	From what I have read. The large hump was in 4x4 trucks and also trucks with turbo 400 trannys. I found this out when I was installing rubber floor mat in my 3/4 ton truck. Good luck with this info. __________________ '72 GMC custom camper 350/350

12-09-2002, 06:29 AM	#3
OhioDan Registered User Join Date: Apr 2002 Location: New Carlisle, Ohio,USA Posts: 1,404	Check out Wes's website at http://classicheartbeat.com/index.html Check page 2 under interiors, and there's a tech tip to explain the difference between low hump and high hump. Hope this helps? __________________ 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.

12-09-2002, 10:12 PM	#6
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,717	MOST big block trucks with autos were high humps as well, but most had TH400s. One exception to this might be 1/2 ton big blocks, especially in Suburbans. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

12-09-2002, 10:22 PM	#7
gashog Active Member Join Date: Oct 2002 Location: Lake co. california Posts: 192	Here's a pic of a low hump in my 69 C/10 turbo 400 small block. Attached Images __________________ 69 Custom/10 454 Turbo 400 and 70 Custom/20 350 Turbo 350, 73 cheyanne C/10 also 69 camaro Z/28 and 85 Iroc Z

12-09-2002, 12:11 PM	#4
Lightspeed Registered User Join Date: Oct 2002 Location: Virginia Posts: 226	high humps were used in trucks that were originally 4x4 or originally came with a floor shift transmission. low humps were trucks that had column shift transmission.

12-09-2002, 04:13 PM	#5
sgtjed What if? Join Date: Oct 2002 Location: Choctaw,Oklahoma Posts: 649	cool thanks guys,i guess i have a low hump then.

12-09-2002, 10:28 PM	#8
Hooter My other Love Join Date: Aug 2001 Location: Castlegar B.C. Canada Posts: 4,085	Hmm I always thought I had a small hump. Now that I see that pic I guess i have a big hump. I have a th400 in my 69. I always thought the large hump cabs had the center hub that was bolted to the cab? __________________ Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life

12-09-2002, 10:42 PM	#9
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,845	I have heard, but never seen one myself, that high humps bolt in, while the low humps, like the picture shows, are integral with the floorboard. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

12-09-2002, 10:57 PM	#10
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,770	Here is a link to where I have the explenation in my helpfull tips section of our website. Pictures too!! http://www.classicheartbeat.com/high_low_humps.htm WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

12-09-2002, 11:17 PM	#11
chevy2racr So Many Ideas, So Little Money Join Date: Sep 2001 Location: Marshalltown, IA Posts: 1,610	yeah high humps bolt in, lows are part of he floor, lows are something like 3-4 inches tall tops __________________ 72 Blazer 3/4 ton running gear 4.10s NP205/TH350 350 4in lift half doors 71 C10 with 454 99 S-10 5.1L SBC 700R4 09 Malibu Marshalltown, Iowa

12-10-2002, 12:03 AM	#12
sgtjed What if? Join Date: Oct 2002 Location: Choctaw,Oklahoma Posts: 649	well that helped a ton,thanks!! i now know i have a low hump.

12-10-2002, 12:36 AM	#13
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	It has been documented that 4 speeds, 4X4's, and big block trucks had high humps....but I suspect that GMC trucks with the V-6 had them too. I know mine (with a TH400) has a high hump....however, the one ton that had a 350/TH400 has a small hump. Here is the high hump bolt in deal in my GMC. Attached Images

12-10-2002, 12:44 AM	#14
gangforward Hootis is as Hootis does... Join Date: Nov 2002 Location: Southern Georgia Posts: 500	If you have a low hump - (327 motor, glide) and are going to convert to a Big Block and Turbo 400, do you have to go to the high hump, or will it fit with the lowhump?

12-11-2002, 12:28 AM	#15
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	most likely....they did at the factory.



Register or Log In To remove these advertisements.

12-11-2002, 04:40 AM	#16
bodad Registered User Join Date: Oct 2002 Location: Tulsa, OK Posts: 106	So, is the low hump welded to the floor. I have a project going that has a HH now but it originally was a LH. The HH has a cutout for what looks like a 4 sp. and I will need to patch it to cover the hole. It is back with the 350/350 setup so I no longer need the HH. Instead of patching the HH would I be able to weld in a LH if I can find one?

12-11-2002, 04:31 PM	#17
chevy2racr So Many Ideas, So Little Money Join Date: Sep 2001 Location: Marshalltown, IA Posts: 1,610	if you find one outta a junked truck you can weld it back in yes __________________ 72 Blazer 3/4 ton running gear 4.10s NP205/TH350 350 4in lift half doors 71 C10 with 454 99 S-10 5.1L SBC 700R4 09 Malibu Marshalltown, Iowa

12-11-2002, 09:14 PM	#18
imdarren Registered User Join Date: Oct 2001 Location: SW Washington Posts: 1,006	So can someone confirm..... You can fit a big block with a TH 400 in a pickup that has a small hump? No clearance problems? Longhornmail may have answered this. But it was unclear whos question he was answering. Thanks, Darren __________________ Washington State 1967 Chevy C10 LWB Rodstoration In Progress. 1972 K20 Cheyenne Super

12-11-2002, 09:41 PM	#19
Dropt72Shortbed Registered User Join Date: May 2002 Location: Huntington Beach CA Posts: 678	can a high hump cab be converted to a low hump relatively easy? i prefer the low hump better but the new cab im purchasing is a high hump can a low hump section be purchased from anywhere or would i have to go cut one out a junk yard cab?

12-12-2002, 12:30 AM	#20
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	darren, I was refering to your Q...but it is mostly speculation. I know it is starting to look like I'll have hump clearnace trouble on my caddy swap...but that don't really cound.

12-12-2002, 09:41 AM	#21
MOTHERTRUCKERS Registered User Join Date: Dec 1999 Location: BRADENTON FLA Posts: 3,269	We have put big blocks and t-400's in low humps without any real problems, on one we had to cut the firewall to floor seam flush in the hump and weld it back together, could have just hammered it flat and it would have worked. __________________ Rest in Peace Ed. Thanks for all the good times.

Register or Log In To remove these advertisements.