GCWR for 94 K1500

LVJJJ

Original poster
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Dec 29, 2015
65
Blaine WA
After 30 years of towing trailer I should know this, but I cannot find the Gross combination weight rating for my '94 GMC K1500 Suburban. One website said the burb can tow 10,000 lbs, that would be a huge trailer for a half ton, so that would seem to be the GCWR but it doesn't say that. The sticker on the door lists 7200 lbs as the GVWR. I'm just under 6,000 so okay there. Our 26' TrailCruiser weighs about 5300 lbs, way under the supposed 10,000 lbs towing capacity, but that seems to put me over what I think is the GCWR. On the way home from our recent 4,000 mile trip, I had the entire unit weighed at a certified scale and combined, it was 11,300. I think I'm 1,300 lbs over weight, right?
 

Reprise

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I found this (on trailers.com):

Year
Make
Model
Engine
Tow Capacity
1994​
Chevrolet/GMC​
Suburban K1500 (4WD)​
All​
6000 lb​
Notes: Requires 3.73:1 axle ratio. Requires Z82 Trailering Special Package._Requires automatic transmission._ Requires engine-oil cooler._ Requires transmission-oil cooler._ Requires weight-distributing hitch._ A higher tow rating is listed for pickups that tow fifth-wheel trailers._​

Remember that your tongue weight counts against payload. If your GVWR is 7200, and the truck is roughly 6000, then you've got 1200 lb of payload. That includes passengers, cargo, etc (and however much of 'you' weighs in > 150lbs).

Generally, TW is about 12-15% of total trailer weight. So...if you know your trailer is 5300 (and we won't go into 'dry' vs. 'wet', right now), 15% of that is almost 800lb (could be lighter, but that's about the max). So... 800# off the 1200# you have... 400# left for family / gear.

I'd say with water, battery, propane, food, etc... you might be right about at the tow capacity of the truck. Will it pull more? Well, you drove 4000mi, with it, so you know...lol. I'd definitely be using a WDH, and a trailer brake controller would be a good idea, too.

Some more info from another site... (all in lbs, unless noted)
Curb weight: 5148
GVWR: 7200
(so, subtracting the first from the second, you have 2,052 payload.)

And, finally, from the GM Heritage site, I found specs for the '95 Burb K1500 (essentially similar)
Max trailer weight is 6000, max tongue 750
(pg 24 of: )

Assuming all is the same between the two years, add your 7200 GVR to 6000 Gross Trailer Weight, and you have... 13,200 GCVWR

Subtract your 11,300 scale weight, and you were 1,900 *under* maximum :2thumbsup:
(but you're right at the max on the trailer, so store any addn'l 'extra' gear from this point out in the Burb, if you're worried about liability concerns from a potential accident, etc.)

Check your axle ratio - you should see 'GT4' on the glovebox label (3.73).
If you have 'GU6' (3.42), ALL of the specs above are out the window (and you were definitely overweight)
'G80' is locking diff / posi

Also from the Heritage site, I saw your trans is coded 'M30', meaning that's a 4L60e.
If you don't already have a tranny cooler on it, get it now. (if you have RPO Z82, as listed above, you may already have a factory cooler)
 

littleblazer

Member
Jul 6, 2014
9,265
I found this (on trailers.com):

Year
Make
Model
Engine
Tow Capacity
1994​
Chevrolet/GMC​
Suburban K1500 (4WD)​
All​
6000 lb​
Notes: Requires 3.73:1 axle ratio. Requires Z82 Trailering Special Package._Requires automatic transmission._ Requires engine-oil cooler._ Requires transmission-oil cooler._ Requires weight-distributing hitch._ A higher tow rating is listed for pickups that tow fifth-wheel trailers._​

Remember that your tongue weight counts against payload. If your GVWR is 7200, and the truck is roughly 6000, then you've got 1200 lb of payload. That includes passengers, cargo, etc (and however much of 'you' weighs in > 150lbs).

Generally, TW is about 12-15% of total trailer weight. So...if you know your trailer is 5300 (and we won't go into 'dry' vs. 'wet', right now), 15% of that is almost 800lb (could be lighter, but that's about the max). So... 800# off the 1200# you have... 400# left for family / gear.

I'd say with water, battery, propane, food, etc... you might be right about at the tow capacity of the truck. Will it pull more? Well, you drove 4000mi, with it, so you know...lol. I'd definitely be using a WDH, and a trailer brake controller would be a good idea, too.

Some more info from another site... (all in lbs, unless noted)
Curb weight: 5148
GVWR: 7200
(so, subtracting the first from the second, you have 2,052 payload.)

And, finally, from the GM Heritage site, I found specs for the '95 Burb K1500 (essentially similar)
Max trailer weight is 6000, max tongue 750
(pg 24 of: )

Assuming all is the same between the two years, add your 7200 GVR to 6000 Gross Trailer Weight, and you have... 13,200 GCVWR

Subtract your 11,300 scale weight, and you were 1,900 *under* maximum :2thumbsup:
(but you're right at the max on the trailer, so store any addn'l 'extra' gear from this point out in the Burb, if you're worried about liability concerns from a potential accident, etc.)

Check your axle ratio - you should see 'GT4' on the glovebox label (3.73).
If you have 'GU6' (3.42), ALL of the specs above are out the window (and you were definitely overweight)
'G80' is locking diff / posi

Also from the Heritage site, I saw your trans is coded 'M30', meaning that's a 4L60e.
If you don't already have a tranny cooler on it, get it now. (if you have RPO Z82, as listed above, you may already have a factory cooler)
:iagree::goodpost: So long as you have that 3.73 you're probably okay. That 7200 seems suspect though... around that time GM made a light duty 2500 and used the same frame. It was a 6 lug truck with the beefed up springs and axles. So in theory you can squeak out a little more... but for insurance reasons you shouldn't... I'm going to stop now.
 

LVJJJ

Original poster
Member
Dec 29, 2015
65
Blaine WA
Thanks Reprise. What you say makes sense. I saw one .com site that said the tow capacity was 10,000 lbs., little high I think. The weights I gave are all actual weights on a certified scale, so no dry or wet questions. (I think the trailer manufacturers dry weight is 3400 lbs, not even close).
The 94 has all of the bells and whistles needed for towing, everything you list above, 3.73, factory external trans cooler, etc. I use an Equal-I-zer WD hitch which keeps our very aerodynamic 2005 26' Trail Cruiser absolutely stable, no sway at all, headwinds don't even bother us much. It is set up correctly. While driving everything feels good, the Burb weighs more than the TT so feels very stable, corners good etc. Just didn't feel like we were overloaded. Problem is, is that low compression 350. I've done quite a few external improvements, adjustable timing control (run 15 degrees advanced), dual 4" air intakes, Fastchip, all AC Delco tune up parts, dual exhaust. Looking at Vortec heads and cam or a 383 Stroker. Keep cracking exhaust manifolds though, maybe I can blow up this engine and she'll have to let me replace it.
 

LVJJJ

Original poster
Member
Dec 29, 2015
65
Blaine WA
Another good point littleblazer (I first posted this in the wrong spot, good thing I did), thanks. The Burb is rated as a half ton 1500 but it weighs almost 6,000 lbs. Three tons just to carry 1/2 ton??? 5920 lbs certified weight. It seems real beefy and it looks more like a 2500 underneath than a 1500, components seem heavy duty, big front and back sway bars, 6 lug wheels.
 

Reprise

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I saw one .com site that said the tow capacity was 10,000 lbs., little high I think.

'Yes and No'. It's an accurate number - but that was for the 3/4 Burb w/ the 7.4 turbo diesel.

Since the 5.7L was the sole engine for the 1/2 ton Suburban that year, 6000 lb is your max, on a bumper pull. Didn't see a rating for a 5'er, but I'm sure it's out there...somewhere!


That 7200 seems suspect though... around that time GM made a light duty 2500 and used the same frame. It was a 6 lug truck with the beefed up springs and axles.

No...I found that in a few different places. He really does have a 7200lb gross on his Burb (his max weight, not the tow rating). That was back in the days where you got some decent payload, even a little more surprising that it's in a 1/2 ton Suburban, I suppose.

Of course, if he had the 3/4 Burb w/ the diesel, it would've eaten up all his payload (but he'd have a 17K GCVWR)
 
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LVJJJ

Original poster
Member
Dec 29, 2015
65
Blaine WA
although the 10,000 lbs listing was for the K1500, never mentioned a K2500. I have noticed that this 94 does seem to have higher weight ratings than most other Burbs. So maybe I do have a stealth 2500. Sure appreciate all the comments, I'm feeling better about my rig situation. Now, to find an engine that will pull all this weight.
 

littleblazer

Member
Jul 6, 2014
9,265
'Yes and No'. It's an accurate number - but that was for the 3/4 Burb w/ the 7.4 turbo diesel.

Since the 5.7L was the sole engine for the 1/2 ton Suburban that year, 6000 lb is your max, on a bumper pull. Didn't see a rating for a 5'er, but I'm sure it's out there...somewhere!




No...I found that in a few different places. He really does have a 7200lb gross on his Burb (his max weight, not the tow rating). That was back in the days where you got some decent payload, even a little more surprising that it's in a 1/2 ton Suburban, I suppose.

Of course, if he had the 3/4 Burb w/ the diesel, it would've eaten up all his payload (but he'd have a 17K GCVWR)
I always forget trucks used to be trucks lol. Thinking about it, that does seem about right I suppose.i think the red truck was rated at 8600 as a 1 ton (3500, used to be printed on the registration strangely the 07 2500hd with the 6.0 was rated at 9000 but the truck weights 7300 or so dry.). That clocks in at 6700 or so with the 350. So a Burban being at 7200 and clocking around 6000 seems accurate, my bad. :yes:
 

LVJJJ

Original poster
Member
Dec 29, 2015
65
Blaine WA
Now that I feel better about the weight, I've got to deal with the fact that I'm apparently overworking the 350 and cracking exhaust manifolds. Had them both replaced a year ago cause the originals were leaking where the bolt heads broke off. Within 6 months I had cracked one and had it replaced under warranty. Just got back from 4,000 miles of towing between here (Blaine WA) to Prescott AZ. Lots and lots of steep hills and mountain passes. Most of the time ran good in 3rd sometimes with converter unlocked, but ok. Up the passes I'd pull it down to second at 55 mph which was about 4,000 rpm and run strong up the pass. Well this time, I cracked both manifolds, one broke completely in half. Apparently you shouldn't run it at 4,000 to 4200 rpm so long. The manifolds have a lifetime warranty, but the labor doesn't, so I'm thinking of going with shorty headers, tired of cracking manifolds, or slow down, or smaller trailer, or better motor (like a 383 stroker). Taking off the manifolds I ran into the power steering pump bracket problem and cut off one of the tabs instead of taking the pump loose, probably will regret that. Anyway, getting a little tired of this Burb, shoulda found a 454, it would get better mileage than the 6-8 we got on this trip.
 
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TollKeeper

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Dec 3, 2011
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Brighton, CO
...but that was for the 3/4 Burb w/ the 7.4 turbo diesel.

You mean 7.4 gas and a 6.5 Turbo Diesel I hope? 😊

@LVJJJ , if you have the Dorman Exhaust manifolds, they had/have a quality control issue or something on the 5.7 manifolds. Thin castings, and cracked manifolds were/are a very common problem. My only suggestion is the one you are already thinking about.
 
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Reprise

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You mean 7.4 gas and a 6.5 Turbo Diesel I hope? 😊

You're absolutely right. Sorry about that! :whistle:


I went back and looked at the powertrain ratings. Amazingly enough, that pre-Duramax TD was *not* the towing top dog - it was ONLY the 7.4L (Mark IV ?) that got the 10,000 lb rating.

The 6.5 TD was rated only slightly higher than the 5.7 base (or 'only' engine for the 1500-series). Here's a screencap to illustrate:

88951

One last thing:

although the 10,000 lbs listing was for the K1500, never mentioned a K2500.

I bring this up b/c I'm in 'provide accurate info' mode... but the people who posted "10,000 tow rating on the 1/2 ton Burb" were lazy in their research, their writing, or both. Here's probably what happened...

Manufacturers commonly advertise along the lines of "... up to <limit> "
But in the fine print, it'll say... "when properly equipped"

Meaning, there's generally ONE config where the 'max' applies...and in this case, it was only for the 3/4 ton, b/c that was the only body where you could get the 7.4L engine (along with a 4L80 trans, which you'd also need for that kind of weight, back then)

Generally, the 4.10 gets rated higher for capacity, but I saw no difference between it and the 3.73, for this particular vehicle.

I don't blame you, OP, but the people who post the info incorrectly.

Yeah, it's a small thing, but it's pretty pervasive on the interwebs. Since I was posting again to this thread, I couldn't hold my tongue any longer.

(said the guy who mixed up the ratings in his own posting, a few days earlier...) :confused:
 

littleblazer

Member
Jul 6, 2014
9,265
I think... and I could be wrong... that the 3/4 and 1 ton manifolds from the later years are beefier and bolt right up... but that could be for a different truck. I do know that the exhaust diameter is larger... roughly 2.75 vs 2.25? On the 1500s and that probably helps with the heat too. What you gain going to shorty headers to prevent cracking, you lose in exhaust leaks at the flange... if they keep cracking I'd bet they warp enough to tick too. If you haven't seen our c3500 383 build yet... and are thinking about building one... don't. Because it's all wrong lol. The HT383 is a good benchmark and you'll probably want something with 300 hp /450 torque to do what you're looking for. :yes:
 

LVJJJ

Original poster
Member
Dec 29, 2015
65
Blaine WA
We're now thinking of selling the 94 since it won't do the job we need it to do. will be looking for newer 3/4 ton 2WD Burb with 6.0. Hard to find I know. We had a 2005 Roadtrek motorhome based on the Chevy Express 2500 with the 6.0. It weighed 8,000 lbs and we towed a 5,000 lb travel trailer with it and it had no trouble at all pulled most mountain passes on cruise control (and got 11 mpg towing) Used to have an '88 Burb 2WD with 454, should never have gotten rid of it. Started towing in 1988 with a 65 Chevy Van (flat front) that I put a 292-TH350 in it and towed all over the western USA for 90,000 miles with not a single problem. Still have it, maybe go back to that (cept it doesn't have A/C and is really noisy inside).

Thanks for all the responses, learned a lot.
 
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TollKeeper

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Dec 3, 2011
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Brighton, CO
Depending on your finances, you could always search for one of those Duramax swapped Suburbans. Those are really cool!
 

littleblazer

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Jul 6, 2014
9,265
Depending on your finances, you could always search for one of those Duramax swapped Suburbans. Those are really cool!
It's a shame GM never offered those.
 

DocBrown

Member
Dec 8, 2011
501
Three tons just to carry 1/2 ton??? 5920 lbs certified weight.

Just for clarification, the terms 1/2 ton, 3/4 ton, and 1 ton haven't actually applied to light duty trucks for probably 50 years. They are terms used by the general public to keep them straight in conversations. You will never see these terms used by manufacturers or dealers. The designations are 1500/150, 2500/250, and 3500/350. A modern 1500 (aka 1/2 ton) can have a 2000# payload.
 

LVJJJ

Original poster
Member
Dec 29, 2015
65
Blaine WA
Got all my problems solved, dropped a remanufactured 383 Stroker in it last month (cost $3800 for engine and install) and it tows like a torque monster should. Built by S&J Engines in Spokane. Likes to run in 4th gear until hit 5% grades, doesn't hunt or unlock the torque converter hardly at all. The trailer we have now is longer but actually lighter than our first 26' '05 Trail Cruiser. Our "new" one is also a 2005 Trail Cruiser but a little different floor plan and is 27' 11" and weighs only 4200 lbs half loaded (true weight at scales). Also got 9.5 miles per gallon on our 600 mile trip to Pacific Beach from Blaine WA. Can't wait to tackle some mountain passes this summer.
 

Reprise

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Got all my problems solved, dropped a remanufactured 383 Stroker in it last month

I'm jealous. :smile: Been thinking lately about building a new / freshened short block for my 6.0 after I get the upper end refreshed in the spring.

Glad to hear you found a solution.
Happy Camping! :wink:
 
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littleblazer

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Jul 6, 2014
9,265
I'm jealous. :smile: Been thinking lately about building a new / freshened short block for my 6.0 after I get the upper end refreshed in the spring.

Glad to hear you found a solution.
Happy Camping! :wink:
*cough* 408 *cough*
 

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