1/2 and 3/4 ton frame differences? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dave's70 · 09-01-2002, 06:50 PM

Is there any differences between a 1/2 ton and a 3/4 frame. If there is what is it?

*Gee_Emm* · 09-01-2002, 07:04 PM

Cab mounts, there was some discussion on here before about the metal being thicker in the frame but I think that we had determined that to be false.

dave's70 · 09-01-2002, 07:15 PM

does that mean you can't use a 3/4 ton cab on a 1/2 ton?

*Gee_Emm* · 09-01-2002, 07:22 PM

No the cabs up to the 40 series I think are the same, I am assuming that the cab mounts are different though because the 3/4 tons use different cushions then the 1/2 tons.

sakohntr · 09-01-2002, 07:56 PM

Well let me start by saying that i took a 3/4 ton two wheel drive cab and put it on my 1/2 ton 4x4 shortbox with no problem. I did use new 1/2 ton cab bushings though. Everything mated up fine.

Longhorn Man · 09-01-2002, 08:20 PM

The cabs are the same 10-30.
The 1/2 ton 2 wheel drive has one mount.
All others have the other mount.
The frame on a 3/4 ton is thicker.

*Gee_Emm* · 09-01-2002, 08:39 PM

I though there was a whole topic a few months back where ppl measured their frames and it turned out that they werent thicker????

Longhorn Man · 09-01-2002, 08:41 PM

Tell you what, i'll go out and measure mine...I need a cigg now anyways. (no smokin in the house)

Longhorn Man · 09-01-2002, 08:47 PM

Too dark, couldn't tell.
Blus I realized...I have a one ton...not a 3/4. (I think of them as the same since the Longhorns are the same 3/4 to 0ne ton)
If I remember, I'll measure in the morning anyways.

**ThreeQuarter** · 09-01-2002, 09:42 PM

Yeah, I'm with Gee Emm. I thought everyone decided that they're all the same gauge thickness (redundant?). Anxious to see what we find out the second time, though.

Longhorn Man · 09-01-2002, 09:52 PM

Either I missed that one, or i already forgot it.
I guess I'll take y'alls word for it.

Beast388 · 09-01-2002, 09:53 PM

I second what gmcblu said. I remember the last thread about this as well. I think that it was determined that they were all the same material thickness. But in case anyone wants to measure again, the frame on my 1/2 ton Suburban is formed from 1/8" material and measures about 6" tall right behind the front cab support frame bracket.

Southpa · 09-01-2002, 09:55 PM

The next time I get hold of the ultrasonic unit from work I'll take a few shots of my frame and then compare with a buddy's 3/4 ton frame.

Rod · 09-01-2002, 10:40 PM

The rear cab mount on the 3/4 ton frame is about 1 inch lower than a half ton frame. A half ton frame the rear cab mount is even height to the top of the frame. 1/2 ton 4x4 ,3/4 ton and 3/4 ton 4x4 and 1 ton trucks all use the same cab mount bushing... but a 1/2 ton 2wd is unto themselves and use a different height... actually smaller rubber cab support bushing.
There is no problemn swapping cabs just make sure you use the appropriate cab support bushing for your needs.
A C40 cab is different. Rod

Here is a pic of the rear mount on a 69 4x4 frame. See how its a little lower.

Giljar · 01-06-2014, 05:55 PM

Anyone hawe the exact measure for how much lower the 3/4T is compered with the 1/2?

I hawe a 1/2 ton 69 and is replacing my frame mounts. By a mistake my new bushings ar for 3/4 ton, so my plan is to make new holes in the frame and put te mounts i the 3/4 location.

Quote:

Originally Posted by Rod

The rear cab mount on the 3/4 ton frame is about 1 inch lower than a half ton frame. A half ton frame the rear cab mount is even height to the top of the frame. 1/2 ton 4x4 ,3/4 ton and 3/4 ton 4x4 and 1 ton trucks all use the same cab mount bushing... but a 1/2 ton 2wd is unto themselves and use a different height... actually smaller rubber cab support bushing.
There is no problemn swapping cabs just make sure you use the appropriate cab support bushing for your needs.
A C40 cab is different. Rod

Here is a pic of the rear mount on a 69 4x4 frame. See how its a little lower.

72MARIO · 01-06-2014, 08:14 PM

That is one thing I have yet to see and clarify.....I have to look in the am at my trucks see what the difference in frame mount locations is

k29349 · 01-06-2014, 08:59 PM

Wondering if anyone here has tried to set a 67-72 k-10/k-20 on a 73 - 87 k-10/k/20 or even k-30 frame? How much of a pain was it?

09-01-2002, 06:50 PM	#1
dave's70 Registered User Join Date: Jan 2002 Location: comox, british columbia Posts: 110	1/2 and 3/4 ton frame differences? Is there any differences between a 1/2 ton and a 3/4 frame. If there is what is it? __________________ 70 C-10 350 with weind intake,eldelbrock carb,HEI,305 heads,a mild cam. also a blazer tank w/bed fill,shaved stake pockets and tailgate

09-01-2002, 07:15 PM	#3
dave's70 Registered User Join Date: Jan 2002 Location: comox, british columbia Posts: 110	does that mean you can't use a 3/4 ton cab on a 1/2 ton? __________________ 70 C-10 350 with weind intake,eldelbrock carb,HEI,305 heads,a mild cam. also a blazer tank w/bed fill,shaved stake pockets and tailgate

09-01-2002, 07:56 PM	#5
sakohntr Registered User Join Date: Mar 2002 Location: Floodwood Minnesota Posts: 1,057	cab mounts Well let me start by saying that i took a 3/4 ton two wheel drive cab and put it on my 1/2 ton 4x4 shortbox with no problem. I did use new 1/2 ton cab bushings though. Everything mated up fine. __________________ 1967 K30 Napco 292/SM420 original paint 30k miles 1968 K60 Napco 396/5spd. dbl frame 52" michelins 1969 K10 SWB GMC 454/4spd 6" 35's posi,hooks 1972 C30 longhorn,BB/AT,A/C,Tilt,Toolbox,lokr 1987 K20 Chevrolet Suburban. 6" lift. 5.7L/TH400 1979 K60 GMC Coleman 4x4, 427/Allison.

09-01-2002, 09:42 PM	#10
ThreeQuarter Senior Member Join Date: Jun 2000 Location: Texan in Iowa Posts: 2,522	Yeah, I'm with Gee Emm. I thought everyone decided that they're all the same gauge thickness (redundant?). Anxious to see what we find out the second time, though. __________________ Ben '68 Chevy C10 Custom LWB 327/TH400 2nd owner '16 GMC Sierra 1500 SLE Dblcab 4wd 5.3

09-01-2002, 09:53 PM	#12
Beast388 Suburbans RULE! Join Date: Jan 2000 Location: Clinton, IA 52732 Posts: 689	I second what gmcblu said. I remember the last thread about this as well. I think that it was determined that they were all the same material thickness. But in case anyone wants to measure again, the frame on my 1/2 ton Suburban is formed from 1/8" material and measures about 6" tall right behind the front cab support frame bracket. __________________ --Ben 71 GMC Suburban 4X4 The "Beast" 388 CID Stroker, TH350, NP205, 8-lug D44, 14BFF w/ Detroit, 4.10:1 gears, 4-Wheel Disks 4" Lift, 35" MT/R's.

09-01-2002, 07:04 PM	#2
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 3,991	Cab mounts, there was some discussion on here before about the metal being thicker in the frame but I think that we had determined that to be false.

09-01-2002, 07:22 PM	#4
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 3,991	No the cabs up to the 40 series I think are the same, I am assuming that the cab mounts are different though because the 3/4 tons use different cushions then the 1/2 tons.

09-01-2002, 08:20 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	The cabs are the same 10-30. The 1/2 ton 2 wheel drive has one mount. All others have the other mount. The frame on a 3/4 ton is thicker.

09-01-2002, 08:39 PM	#7
Gee_Emm Account Suspended Join Date: Sep 2000 Posts: 3,991	I though there was a whole topic a few months back where ppl measured their frames and it turned out that they werent thicker????

09-01-2002, 08:41 PM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Tell you what, i'll go out and measure mine...I need a cigg now anyways. (no smokin in the house)

09-01-2002, 08:47 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Too dark, couldn't tell. Blus I realized...I have a one ton...not a 3/4. (I think of them as the same since the Longhorns are the same 3/4 to 0ne ton) If I remember, I'll measure in the morning anyways.

09-01-2002, 09:52 PM	#11
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Either I missed that one, or i already forgot it. I guess I'll take y'alls word for it.

09-01-2002, 09:55 PM	#13
Southpa Registered User Join Date: May 2000 Location: Victoria, BC, Canada Posts: 2,409	The next time I get hold of the ultrasonic unit from work I'll take a few shots of my frame and then compare with a buddy's 3/4 ton frame. __________________ 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.

09-01-2002, 10:40 PM	#14
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	The rear cab mount on the 3/4 ton frame is about 1 inch lower than a half ton frame. A half ton frame the rear cab mount is even height to the top of the frame. 1/2 ton 4x4 ,3/4 ton and 3/4 ton 4x4 and 1 ton trucks all use the same cab mount bushing... but a 1/2 ton 2wd is unto themselves and use a different height... actually smaller rubber cab support bushing. There is no problemn swapping cabs just make sure you use the appropriate cab support bushing for your needs. A C40 cab is different. Rod Here is a pic of the rear mount on a 69 4x4 frame. See how its a little lower. Attached Images __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.

01-06-2014, 08:14 PM	#16
72MARIO Registered User Join Date: Nov 2000 Location: Huntsville Ontario Canada Posts: 4,051	Re: 1/2 and 3/4 ton frame differences? That is one thing I have yet to see and clarify.....I have to look in the am at my trucks see what the difference in frame mount locations is __________________ 1968 Suburban numbers matching all original truck now equipped with 6.0/4L80 on Accuair http://67-72chevytrucks.com/vboard/s...d.php?t=625017 1967 C/20 6.0/4L80 Roofing Truck 1990 V2500 Suburban "Plow Truck" 2005 TAHOE DD



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01-06-2014, 08:59 PM	#17
k29349 Registered User Join Date: Nov 2013 Location: Inman S.C. Posts: 67	Re: 1/2 and 3/4 ton frame differences? Wondering if anyone here has tried to set a 67-72 k-10/k-20 on a 73 - 87 k-10/k/20 or even k-30 frame? How much of a pain was it?

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