GMT800: 1/2T vs 3/4T for towing 7K

Hello all, first time poster here, long time reader. Figured I'd post up here since this forum by far seems to have a membership that really uses their trucks and understand their capabilities. I am considering buying a GMT800 ('00-'06) for use as a daily driver in the cold months here in WNY and to tow trailers during the nice seasons.

With two little kids I plan on purchasing a travel trailer next year, which will probably weigh in the vicinity of 5-6K lbs itself, not including all our gear, family, etc. I also pull a race car on an open trailer about 3-4 times a year, probably close to 7K lbs in total. Our geography in NYS is not very mountainous, mostly flat, and I don't really plan on any real off-roading unless at a campsite on state land.

Given what I plan to tow, and for peace of mind, I'm looking more at the longer wheelbase Suburban and Yukon XL rather than the shorty Tahoes and Yukons. I also plan on sleeping in the back of the truck on occasion during race weekends, so the extra space is nice.

Will a typical 1500 series Suburban 5.3 be adequate for this kind of duty, or should I expand my options to the 2500 with a 6.0/4L80E? The 2500 seems to command quite the premium over the half ton. I have about a decade of swapping LS motors into cars they didn't come in, so I have no problem dropping in a freshened up 6.0 with a cam and rebuilt 80E. The question is really the rest of the 2500 architecture. If I'm staying reasonably within the tow capacity of a 1500 (8Kish lbs), will I really need the 2500's massive axles, frame, etc that add overall weight to the vehicle? The 8.1 doesn't interest me due to fuel economy and my lack of familiarity with the big block engine.

The hot rodder in me is dreaming up buying a lower mileage (sub 100K) 1500 Suburban with no rust and clean body, installing a freshened up 4L80E with an HD2 kit, and putting together a small, responsive turbo kit (10 lbs boost or so) while retaining the stock cam. I put together a fun little 2002 RCSB 4.8 Stepside with a turbo and 80E a few years back and although I never towed with it, it was a riot on the street while still comfortable.

Rear air helper springs to combat squat and maybe a weight distribution hitch would be inexpensive way to add stability.

So what say you - stockish 2500 6.0 or hopped up 1500 5.3?

I tow 7-8K with my '17 Suburban with no issues, aside from squat. I don't have a weight distribution hitch setup, because we tow 4 different trailers, and I don't want to deal with 4 set ups.

Air helpers would help immensely, but it's not worth it for me as I use my 3/4T Dodge for heavy hauling or longer trips. 

For your use I don't think the 2500 is necessary, but it may be easier and cheaper to find a clean one vs upgrading a 1500. When I was looking finding a decent sub was hard enough and the 2500s definitely were cleaner and lower mile examples overall. 

I tow with my Escalade ESV, squat isn't a problem because of factory air shocks. It is rated at 8,300 lbs. I don't think I have towed more than about 6500. With an open car trailer it tows awesome, my camper is like a big sail so it works harder for that. If you are towing less than 3-4 hours I am sure it is fine. When I towed my camper to NC and I was 7-8 hours at the wheel it was a bit of a beating for the driver (me), however that is a very limited case for me.

What all are you planning to have in the suburban with you? I think payload might be a bigger factor for you, especially with two kids and their stuff.

From a quick search:

2006 Suburban 1500: 7,200 GVWR - 5,505 Curb = 1,695 lbs payload

2006 Suburban 2500: 8,600 GVWR - 6,074 Curb = 2,526 lbs payload

A 7,000 lb trailer needs 10-15% tongue weight which is 700-1,050 lbs. That leaves 995-645 lbs for all people, luggage, toys, snack cooler, pack-n-play, strollers, and any other accoutrements that kids seem to need.  If you are on the lighter end of the tongue weight and weigh less than the average american family, you might be fine with the 1500. If you do a little more tongue weight (which I perfer) and weigh closer to what an average american family weighs, you will be at or over the payload of the 1500. Also, remember little kids turn into teenagers. If you are towing a couple times a year and within a few hours of home you might be fine with the 1500. If towing monthly and muti day trips, I would spend the extra for the 2500.

I had pretty much the same requirements when looking for a replacement truck and ended up with a ram 2500 because of the payload. Would the 1500 have worked? Maybe. The 2500 is a lot more stable when towing.

I have a 2004 Suburban 2500 8.1. A buddy I race with had the same truck with a 6.0 for a while. He got about 1 mpg better than I did unloaded, and about 1 mpg worse towing a moderate load. The 8.1 is a dramatically more relaxed towing experience because the 6.0 was spending a lot more time in 3rd gear over 3000 rpm where the 8.1 chugs along in 4th at 2300.

My parents have a 2003 Tahoe with the 5.3. I've not towed my trailer with it, but it gets about 14.5 mpg average unloaded which is 2 mpg better than my 8.1. The 5.3 would handle the open trailer no problem. It would probably be doing a lot of revving with the travel trailer because of the aero drag, but it would probably get it done. Not sure what gears the 1500s came with, I'd be pretty set on 4.10s if they were an option with the 5.3. 

My usual trailer is a small toy hauler that weighs 4700 lbs ready to camp. You're talking about a heavier trailer than that, with the same aero drag, plus more payload than I typically run with. While your race trailer is heavier, it's actually the easier tow (my opinion) because the aero drag is so much lower with an open trailer. Travel trailers are TALL and are huge sails. My '98 K1500 towing maybe 6000 lbs of race car and trailer wasn't a big deal. Towing my little toy hauler with that truck was a foot-to-the-floor struggle if there was a hill or wind. 

The 1500 trucks have the 10 bolt 8.6" rear end, they don't like long highway trips overloaded. I've killed one and have another that's on the way out (bearing noise and R&P wear on both), which is what prompted me to move to a 2500. They were in GMT400 trucks, but it's the same axle hardware. I was over the axle weight rating by a bit, but caveat here is I have no idea what the service life of those two vehicles was before I got them.

The wildcard here would be a Yukon XL Denali or an Escalade ESV. 1500 chassis, but comes with the 6.0 and 4L65E. A little more efficient than a 2500, a bit more comfortable unloaded, and they don't have the price premium. Still has the 10 bolt axle though, so payload capacity could still be a problem. 

We used to tow our race trailer, 5-6k loaded, with a GMT800 Yukon XL Denali. It towed just fine. The air suspension was nice to keep a bit more level as we were very cognizant of proper tongue weight. Trailer brakes would have been nice. We are now towing the same setup with a GMT400 Suburban 2500. The older suburban handles the tongue weight better and feels much more stable at speed. Also, it's got a brake controller which is kinda cheating.

The Denali has been a great vehicle for my friend. He is past 440k on it, second trans and second rear end. 20 years later it's still plenty comfy and powerful to tow, but I would rather have a less loaded trailer behind it.

I see a lot of the higher end 1500 Yukons and most if not all the Escalades have the 6.0 instead of the 5.3.

Don't forget about stopping it. 

3/4 ton and up get beefier everything, including brakes.

I quit towing with "just enough" truck a long time ago and I've never regretted switching to a 2500 or better.

I used our 2000 Suburban 1500 5.3 for towing for many years. It really struggled in the mountains, even just towing my little sports cars. Finally killed the transmission (no surprise on these) and upgraded to a 2001 F250 with the V10. Pulled the trailer last night, honestly felt like I did not have a trailer behind me, which was a real surprise. Also the trailer pulled much smoother than it ever did with the Suburban. I am picking up a TR250 project this weekend, so will report back with a load, but so far, I would definitely recommend a 2500 series if you will be doing much towing.

I tow with an 08 Yukon and it works great for towing my 6k+ open trailer. It has the 6.2 but I know people that tow with the 5.3 and don't have a problem either, just take it easier. A weight distribution hitch makes a big difference in handling too and throw some air bag helpers on too. Mine is the short wheelbase so if you get the XL will handle even better. Of course a 3/4 ton will tow better but it will also hurt the daily driver comfort a bit so for your use sounds like a 1/2 ton will be better all around. 

It's going to come down to the specific trailer.  If it's a good quality trailer, properly loaded then you'll be fine pulling it with a 1500 even at 7k.  Unfortunately, there are a lot of crappy travel trailers out there.  I've been renting some as my wife and I decide if that's something we want to own and OMG some of them tow really badly.  I'll pull my 8k 24' enclosed car trailer all over the country with my RAM 3500, often with the cruise control set at 82 MPH. One of the trailers we rented was 5.5k and I wasn't comfortable with it at anything over 75 MPH.

If you're going to use a Suburban for truck stuff get a 2500

It isn't just power, the suspension and drivetrain on a 3/4 ton are able to handle the load better.  You will exceed payload before tow weight capacity, try to keep at or below 75% of limit numbers.  And in a half ton make sure you have a shift kit and separate trans fluid cooler.  A trans temp gage is helpful, and consider adding a leaf or two to the rear springs.  By the time you do all that a 3/4 ton truck might be a better choice.

Ganging up here like a broken record:  Whenever possible, choose the 2500.  "Seems okay" and "just enough" will result in problems that could easily be avoided with "more than necessary."

I used to do track days with a guy who always had a 3500, and even a toterhome at one point, then, in a fit of downsizing, he decided to try out a new 1500 (because nice unladen ride stock) for towing his remaining track car (Idaho to CA).  He did it once, then returned to the dealer shortly after to get another 3500.  The consensus was quickly "hell no."

Besides the advantages of heavier frames/springs/brakes, 2500s have another one to consider: transmission

GMT800 1500s** come with 4L60E/4L65E, I believe, anything with 8-lug axles has a 4L80E with the 6.0L, or an Allison with the 8.1L. Less certain about what trans came with the 8.1, tho.

The 4L80E won't do anything for MPGs, but apples/apples in mileage/maintenance history are much more tolerant of load/towing/abuse.

If you do go with a 4L6xE setup, the trans will be a potential weak link. Stack the odds a little better in your favor: use tow/haul mode. Add a trans temp gauge. Flush & fill with a synthetic lube. Add a trans cooler, if it doesn't have one.

** They did make the "1500 HD," which I believe amounted to the 6.0L, 2500-spec axles, springs, brakes and the 4L80E on a 1500 cab/frame. If I'm not mistaken, these were also one of the earliest true 4-door 1500s GM made. My personal unicorn is a southwestern white 1500HD, bordello-red fabric interior, 2WD, <100K miles. Probably missed the tide for that, but ... only takes one ...

In reply to eedavis :

The 8.1 came with the Allison in the trucks and the 4L85E in the Suburban, Yukon, and Avalanche. Same as the 4L80E with a different valve body and another gear in the planetary I believe. 8.1 trucks and SUVs also get the full floater rear axle and a beefier transfer case where the 6.0 versions I believe have a semi float rear axle.

Some time spent in the tune can make the 4L60E work and last much longer, but the 4L80E is a better trans for heavier stuff (obviously). Less obviously, the gear ratios of the 4L80E.

I just spent a day towing this around, which is ~7500 lbs. Very relaxing, never needed to worry about brakes, sway, cooking the rear end climbing hills, or anything else. 3.73 gears meant 2500 rpm at 78ish mph and the transmission stayed in 4th gear with the converter locked the entire time. Like everyone else is saying, a relaxing experience counts for a lot.

When you've been driving for 10 hours and the kids are screamy and whiny and you are trying to climb through one last mountain pass searching for a campground before nightfall, you'll be thankful you are driving a 2500. 

2500, 8.1, 4l85E towing 9400 lbs like it's not there, even over mountain passes. And when the inevitable trailer blowout happens, it's towing capability is high enough that there's no drama in simply pulling over without losing composure.

As others have said, having a bit more than enough capability is better than a bit less than enough capability. The problem is clean 2500s are going for $10-15k easily, even with high miles.

I have towed my steel open deck trailer and 2500# racecar with all the spares all over the country with my 1500 ailverado 5.3.  No problems.  Probably about 7k lbs loaded.

A 1500 is gonna be just fine as long as it's not worn out.  

A lot of "all over the country" is really flat.

I love watching all the half-ton heroes from Alberta disappear as soon as we hit the mountains.

https://en.wikipedia.org/wiki/Coquihalla_Summit

This climb in B.C. tests your truck. The pullout at the top is always full of Dodge Rams with burnt up transmissions.

When the highway opened, UR Quattro's were catching fire on the climb because the car stayed on boost for so long.

They even made an overly dramatic TV show about it.

This is why I tow with more truck than I need.

Let's face it, a 4L60 is kinda like nipples on men. It's just decorative.

ShawnG said:

A lot of "all over the country" is really flat.

I love watching all the half-ton heroes from Alberta disappear as soon as we hit the mountains.

Towed from PA to NY, Wv,, OH, CONNECTICUT,  SC, Florida, California, Alabama, Michigan, Wisconsin, Colorado, Missouri, Indiana, Iowa, Virginia, etc...  

Truck did great!  No problems.  My nipples (er 4l60) works great!

Just can't go 90mph uphill.  Does fine at 75.

Good trailer brakes makes it fine on the downhill too.

190k on my 2015 1500 silverado with the 5.3.

The 1500 makes the daily grind of taking the kids to school,  driving to work, etc just fine as well.

As you said, most of the country doesn't require a big truck cause it's fairly flat.  You live in some serious mountains, sure.  If not, a 1500 is fine.

If you're not using a 2-5/16" ball, are you even towing? 

I've been watching this thread and finally have a few minutes to chime in. I've got a good bit of experience towing and review new trucks/SUVs for their trailering behavior on YouTube. My first tow vehicle was a GMT800 Yukon Denali (short wheelbase) with the 6.0 / 4L65.

Wheelbase wise - you are looking at 116" on Tahoe vs 130" on Suburban. Big difference and for your use, Suburban or Yukon XL all day long.

Payload is your other big concern given you have two kids so presumably a family of four plus all your stuff plus the tongue weight of the trailer. The maximum listed payload for a 2005 Suburban 1500 is 1,732 pounds. Travel trailers/campers are notoriously more heavy than manufacturers claim so let's assume 6500 lbs for yours. Take 10-12% tongue weight (780 lbs at 12%) and your leftover payload is 952 lbs. You're gonna get close to max payload with the whole family and luggage in there. What if the kids want to bring a friend? Or you bring the grandparents one weekend because you've got that third row? I... probably wouldn't.

My other potential sticking point with the GMT800s is the drivetrain. Those four-speeds have some pretty long gears; they are fine until they're not regarding powerband. I had one memorable instance with my Denali (with an open trailer + Volvo 240 in the mountains) where my two options were about 42 mph in 3rd or 60ish in 2nd. It was lugging in 3rd so I let it scream in 2nd. Painful. The 5.3L would've been worse.

I hate the GMT900s but they do gain the 6-speed automatic which helps make the most out of the engine and tows far better as a result.

I guess if you have to have a GMT800 – which I understand, they look fantastic and IMO are "peak GM truck" ever built – I'd recommend a Suburban 2500 and ideally with the 8.1L. At least if you got one with the 6.0 it'll have payload to spare and the stronger 4L80 transmission. 

Typical advice here about weight distribution + sway control hitch and electronic trailer brake controller apply. Don't tow without 'em.