GMT400 Suburban as Base Overland Rigs?

[nitro_rat]

Why is the 800 chassis better to drive than the 900 in the fun to drive department?

IMO the 800 chassis does everything the 900 does without many drawbacks. Drawbacks of the 900 platform include but not limited to:

-Higher buy in price
-Rack and pinion steering
-MDS
-plastic bumpers
-crappy plastic interior
-complex electronic climate control system
-"screen" in dash

I realize that I am in the minority but I don't like any of these "improvements." If you do than by all means a GMT900 might be for you. The coil spring front suspension is probably an improvement over the torsion bars.

 

[Buddha.]

Why is the 800 chassis better to drive than the 900 in the fun to drive department?

He doesn’t like the heavy/stiff ride of his 2500 compared to his 1500.

 

[CrazyDrei]

Why is the 800 chassis better to drive than the 900 in the fun to drive department?

AutoZealot,

Great question. My GMT800 is a 1500 or 1/2 ton. My GMT900 is 2500 or 3/4 ton. I tuned my 5.3 to the same hp and torque as the 6.0 and I adjusted the transmission shift points and pressures to extend the life of the 4L60E and compliment my driving style, 6L90E is stock and shift points are not ideal. 1,0003 less to move around GMT800 is zippier than GMT900.

In GMT800 torsion bars are gone and replaced with coilovers, yaw and pitch of the front end is gone. It rides better with coilovers and no front sway bars than torsion bar and sway bar. 37" tires add upto 8" of front axle travel off road. The way it's set up I can do a 400 mile Death Valley trip in one day with two toddlers, which I have done weekly for two years, same route would take 2-3 days in the GMT900.

GMT900 has stock suspension with nitrogen shocks. HD suspension when empty is so bone jarring and rough that it is uncomfortable even on pavement if there are any cracks or potholes whats so ever.

My GMT900 is set up for highway only and towing a 10,000# trailer. My GMT800 is set up for fast and technical desert running and off-road focused adventures.

To each their own but lighter weight, smoother and longer travel suspension makes it more comfortable and fun to drive. If both were stock, on same size tires with same tire pressure, the ride difference would not be as noticeable but mine is heavily modified on a $1,000 budget.

 

[AutoZealot]

To each their own but lighter weight, smoother and longer travel suspension makes it more comfortable and fun to drive. If both were stock, on same size tires with same tire pressure, the ride difference would not be as noticeable but mine is heavily modified on a $1,000 budget.

I can get some of your perspective, but it doesn't feel like you're giving the 900 a fair shot in the sense that you modified the 800 for the intended purpose and comparing them for the same job even though the 900 has a different purpose for you at its current configuration.

Plastic Bumpers = nearly ideal competition cut front and rear for aftermarket bumps
Stiff Rear of 900 = Remove all but the upper two leaves and the overload leaf to soften the rear of the truck - supplement with airbags since you tow
ride overall = shocks and swaybar disconnects + what I said above about the rear suspension
rack and pinion bad because perception of weaker? < curious here
I'm highly surprised you find the 800s interior better than the 900.
MDS - 3/4 tons didn't get MDS - since they are not subject to fuel economy standards
LY6 engine - is an iron block 6.0 with LS3 style heads - if you thought the 5.3 woke up with some tuning - play with the new toy and see where it goes

 

[CrazyDrei]

He doesn’t like the heavy/stiff ride of his 2500 compared to his 1500.

Buddha,

Yes, the stiffer ride of the HD platform is inferior for my application. I am also a minority here. I do what most people here dream of and build to do only getting out once a year on an epic trip which I did weekly for couple years. I do not know anyone else who has done Steele Pass, Lippincott and Echo Canyon in Dath Valley in one day let alone with two toddlers. Or all 138 miles of Mojave Rd out and back in one day.

With that said, for most people who spend more time on pavement a 2500 chassis loaded up with 1-2,000lbs of gear that looks cool or you think you need will ride similar to my 1500 chassis loaded with minimal gear. My truck is permanently equipped for 4 people to live in it comfortably for two weeks. I travel with 4 year old, 3 year old and a 6month old. Heavy duty suspension of 2500 makes it impossible to travel faster than 20-25mph over desert washboard without causing shaken baby syndrome. Same washboard in my GMT800 my kids fall asleep as the truck gently rocks them to sleep at 50-60mph.

Ultimately the ride quality between a stock 1500 and 2500 is not that much however my GMT800 is heavily modified for something very specific and the more I compare the two the more I realize that it is a highly biased comparison that will not apply to most people in this forum.

 

[CrazyDrei]

I can get some of your perspective, but it doesn't feel like you're giving the 900 a fair shot in the sense that you modified the 800 for the intended purpose and comparing them for the same job even though the 900 has a different purpose for you at its current configuration.

AutoZealot,

You nailed it. My GMT800 is built for extended off road travel and GMT900 is virtually stock to the point where the front bumper will scrape if I try driving up two steps.

I am waiting for my wife to finish school and I will be doing an exactly the same setup with the GMT900: 3" body lift, 40" tires, better bumpers to give the two a fair comparison on and off road.

 

[usanumber1]

I love my 1999 GMT400. A 350 or 454 GMT400 is a reliable and inexpensive truck with lots of potential. Keep in mind that any potential roof racks or bumpers or interior storage or whatever will be almost exclusively custom as the truck was never marketed in this manner like the Toyotas and Land Rovers.

If I were to do it all over again I would go for a 2001 K2500 GMT800, if only because the SAS options are better, stock rear axle is a 14bff with discs, good condition pickapart parts are generally easier to come by, and my current Cummins swap would be easier.

 

[cst10]

1996 K2500 6.5TD reporting in.

If you're looking for bang-for-the-buck, the K2500 GMT400s are a solid choice. If you can find a K2500 GMT800 in-budget, it's a much better chassis with better aftermarket support. I will say that the slimmer proportions of the GMT400 are very welcome at times, I love mine so far for truck camping and longer trips.

 

[Old Griz]

I run a 1998 K2500 Suburban here in the PNW and I don't see a point of a lift. Reason I went with a Burb over the truck was they are easier to find, and when you do they are normally cheaper for some reason. I plan to use it for some hunts where I will just camp out in the back and it will have more then enough space and be comfortable.

Most of the roads I have found around here don't require much clearance but require some skill to get thru. When I took it the Grand Mesa in Colorado I took it down some really technical roads and it made thru just fine.

Mine is the 7.4l with the towing package so it only gets about 12-13mpg on the freeway. In town it gets around 10 ish. Towing I saw 9-12 mpg. It has been solid and comfortable for some of the longer trips. Just have had random failures due to old age. Still will get in it and drive it Colorado again in a heart beat.

I've got a similar 2001 k2500 8.1 4:10 gears. It works perfectly for me for overlanding/camping.
I don't rock crawl with it so I don't need a ******** ton of flex. I may go the Kryptonite and RCV line if I win the lottery some day
I have Cooper ATP 285/75/16 on it and have been more than happy with them.

Sent from my Pixel 3 XL using Tapatalk

 

[Patrick.S5]

If one were to put an LS-engine into a GMT 400 Suburban, could a 5.3 or 6.0 truck's fuel pump fit in the 42 gallon GMT 400 gas tank?

 

[zoomad75]

If one were to put an LS-engine into a GMT 400 Suburban, could a 5.3 or 6.0 truck's fuel pump fit in the 42 gallon GMT 400 gas tank?

A 96-99 (vortec) equipped truck would have a fuel pump that delivers the same fuel pressure required for a LS engine at 55-62 psi. If you were starting with a 95 and earlier GMT400 it's just a matter of swapping in a AC Delco EP381 pump onto the existing fuel module vs the stock TBI low-pressure pump.

 

[WestcoastD]

SAS THE THING! Can make an epic rig thats comfortable to travel around in with 2 people or multiple people. Most importantly its fairly cheap if you got a welder

 

[lilkia]

Nice Burb! That is very nicely done. Im sure delusional will be in soon to tell you that a ifs coil sprung 1500s with 37s is so much better.

 

[lilkia]

OP either the 400, 800, or 900 k2500 will give you a seriously stout platform to start with. The underpinnings of the gmt800 and 900 are exactly the same. On the 400 youll find either the 5.7, the 7.4 or a 6.5 diesel. The 800 will get a 6.0 or 8.1 and 900 will have the 6.0. None of the 2500s have the stupid emissions valvetrain crap that later 1500s have. Some people will try and say the 5.3 can be tuned to match the 6.0 or 8.1 which is laughable. It may put out similar max hp and torque numbers as the 6.0 but if you look at the rpms needed to generate those numbers on the 5.3 compared to the 6.0 youll see the joke. Comparing the 5.3 to the 8.1 is just stupid. The 8.1 creates more torque at idle than a tuned 5.3 can at redline.

The 2500s have beefier control arms, much stronger wheel bearings and hubs. If you read all the burb threads youll see the 1500 guys trying to turn them into 2500s with rear axle swaps and even changing out the front diff housing for the larger 2500 version. The 2500s come with the 14bolt semi float or the venerated 14bolt full float. Most 2500 burbs Ive seen have the FF version. The 400s are drum rear but they are massive and work very well. All 2500s have stronger front brake setups with thicker discs which are less prone to warpage under heavy use.

The 2500s (early 90s may have the th400) also all come with the 4l80e trans over the 4l60e (prone to failure under heavy vehicle use. Its what they put in cars) and all the 2500s come with factory trans and oil coolers that the 1500s dont. They also have steering pump coolers. Plus the 2500s have larger fuel tanks.

The worst thing about the 1500s is once you put your family in you dont have much gvw capacity for lots of gear or towing. The best analogy is the 1500 is for soccer moms to take the kids to practice. The 2500 is for dad to take the football team and tow the equipment trailer to the game.

 

[Mosinguy1]

OP either the 400, 800, or 900 k2500 will give you a seriously stout platform to start with. The underpinnings of the gmt800 and 900 are exactly the same. On the 400 youll find either the 5.7, the 7.4 or a 6.5 diesel. The 800 will get a 6.0 or 8.1 and 900 will have the 6.0. None of the 2500s have the stupid emissions valvetrain crap that later 1500s have. Some people will try and say the 5.3 can be tuned to match the 6.0 or 8.1 which is laughable. It may put out similar max hp and torque numbers as the 6.0 but if you look at the rpms needed to generate those numbers on the 5.3 compared to the 6.0 youll see the joke. Comparing the 5.3 to the 8.1 is just stupid. The 8.1 creates more torque at idle than a tuned 5.3 can at redline.

The 2500s have beefier control arms, much stronger wheel bearings and hubs. If you read all the burb threads youll see the 1500 guys trying to turn them into 2500s with rear axle swaps and even changing out the front diff housing for the larger 2500 version. The 2500s come with the 14bolt semi float or the venerated 14bolt full float. Most 2500 burbs Ive seen have the FF version. The 400s are drum rear but they are massive and work very well. All 2500s have stronger front brake setups with thicker discs which are less prone to warpage under heavy use.

The 2500s (early 90s may have the th400) also all come with the 4l80e trans over the 4l60e (prone to failure under heavy vehicle use. Its what they put in cars) and all the 2500s come with factory trans and oil coolers that the 1500s dont. They also have steering pump coolers. Plus the 2500s have larger fuel tanks.

The worst thing about the 1500s is once you put your family in you dont have much gvw capacity for lots of gear or towing. The best analogy is the 1500 is for soccer moms to take the kids to practice. The 2500 is for dad to take the football team and tow the equipment trailer to the game.

i just aquired a 1996 2500 suburban to go with my 86 lifted 1500 do you think a 3 in body lift with 35s would be easier and better than a torque key and leveling block lift?