3/4 vs 1 ton differences & upping GAWR?

[columnshift]

What are the differences between heavy duty 3/4 tons and the 1 ton pickups? And is there any reason you can't just swap parts over to up the cargo capacity for instance? Like if I stuck 1 ton parts under a 3/4 ton suburban could I haul even more weight in the back? I had thought I read the frame of the 3/4 ton was the same as the 1 ton, it's just running gear that differs.

If I put in even stouter parts than a 1 ton (like a Dana 110 rear and Dana 70 front, brakes and oversized air springs for when going heavy) could I potentially load even more than a 1 ton in the back? (note i'm planning neither of those, that's just an overkill example so nobody says the axle isnt strong enough)

I guess i'm wondering at what point frame upgrades would either be needed or suggested, or things like boxing the frame or adding extra crossmembers or if that's not enough at some point... I mean normally what I read about tow limits is along with general ratings it's 'tire rating, axle rating' to not exceed so if both of those are upped whats the next problem area?


Note i'm not planning on doing any of the above with regularity! Rather it's more wondering that if I made certain upgrades to a 4x4 as is often done to take off road abuse, if I could also give it sort of an overload capacity to be usable in a pinch... which I don't think i'd run over 30mph or maybe the 40mph forced on the highway anyways max hopefully only for a shorter distance.

You could well say "get a superduty" or 4-series but what i'm curious is that if superduty level loads are rare enough if there's a way that upgrades i'd be doing anyways could fulfill double duty for the few rare times I might want the capability since the 4-series would be overkill 98% of the time.

 

[bucket]

There were a lot of differences between 3/4 ton and 1 ton, some major and some minor, and it varied through the years. Besides axles, 1 ton frame rails are taller.

If you want the ability to tow a good load, run a strong motor and trans, 1 ton axles, and a set of 8 or 9 leaf 56" springs in the back with some air helper springs. And a trailer brake controller. Then tow whatever the heck you want with it, it will be fine. Even if there's the occasional big stupid load.

 

[columnshift]

I'm sorry if i'm just full of questions but it's more a concern about the payload/behind the rear seat load than the tow rating... maybe this is "I don't know" territory but i'm just seeing if anyone's ever considered it (or has intelligent guesses at where to upgrade) before.


Thinking out loud... I wonder if it would it be feasible to simply stick a 3/4 ton suburban body (or even a 1/2 ton suburban which there seems to be more of/i'm assuming there's no real BODY differences in terms of strength issues, just frame and running gear?) onto a 1 ton frame? (i'm guessing length might be an issue requiring cutting, welding, and gusseting the frame so it can't be a weak spot) I'm assuming frame rail height shouldn't matter unless the shape was different.

From what I can tell 3/4 ton suburbans are less common than 1/2 tons.. making me consider chassis swap from another angle since i'm looking a frame-off restore/modification anyways.


I was guessing 1 ton powertrain on a 3/4 ton chassis would take heavy tow loads, I was more wondering about the sprung weight above the axles than on the hitch. Normally the 2700lb 3/4 ton payload would be enough, but i'll be eating 1000lbs of that just going with the diesel/trans combo i'd ideally like even before stupid-large fuel tanks for cross-country no-stops travel... (does anyone make a 200gal??? not even joking that much, want 120 minimum if I can) since I don't want to speed (excessively) and stops REALLY take down your average. Instead of speeding 10 over just not stopping saves the same time with better MPG.

And i'd still want my 2700lb cargo capacity (or even a little more - if I keep all 3 bench seats and throw 8 big Ojibwe in there with me i'm probably over that especially once were hauling something back behind the seat) inside the 'Burb itself. My "effective" payload capacity (even if much weight is hooked to the frame rails, not inside the cab) would probably be more like 5000lbs like it seems 1 tons are more often rated in payload... or I mean the same GVWR as a 1 ton.

I'm aware what is probably ideal is a 1 ton van - but I don't want a van (not even a 4x4 one) I want a suburban. I might reduce some of my wishlist if it's unfeasible but i'm hoping it's not.

 

[kleedus]

what will you be hauling that will fit behind the seat that would weight that much

1 ton frames are taller under the cab and the rails are made from thicker metal

sounds like you should get a c 60 truck and put a sub body on it I think that would be far less work than making a half or 3/4 ton sub do what you want

a c60 is a 2 ton truck

you can get a c60 with a 2 speed rear axle

 

[kleedus]

I have read your posts threw a couple times and I am more confused than when I first read them.

what do you want from this sub

diesel engine swap extra payload and huge fuel tank for cross country trips ?

for what purpose what will you be doing with it the cargo area behind the seat is small even with the third row removed I don't know what you would put in there that could weigh that much.

I think you might be over reaching for what a suburban can do.

put a dana 60 up front 14 bolt out back with the 1 ton brakes or upgrade to disc rear brakes. put a set of 1 ton leafs in it with air bag helpers. and get a trailer to haul your weight.


what will you be hauling cross country that would require these mods and how often. would it make a custom purpose built truck from the ground up be worth it

 

[marks86]

sounds like someone needs to buy a duramax

 

[skysurfer]

And i'd still want my 2700lb cargo capacity (or even a little more - if I keep all 3 bench seats and throw 8 big Ojibwe in there with me i'm probably over that especially once were hauling something back behind the seat) inside the 'Burb itself.

Don't underestimate how sturdy a 3/4 ton burb is. I use mine to carry as much weight as anybody. An average load is nine people and their gear, but I've carried 13 and 600 lbs. of gear on many occasions which is in the 3300-3500 lb range. And that's offroad crawling up some really steep trails. Only modification for the extra weight is some Ride Rite helpers pumped up to 40 psi. Been doing this for 14 years with the same vehicle and have had no issues.

 

[MadOgre]

Well if you stuff a 14 bolt FF rear end in you don't have to worry about axle failure due to stress, That's what they were made for. so then its just making sure your suspension is up to eh task, next in line is to ensure you have no weak spots in your frame like rusted out areas and that all brackets cross members are properly secured like no missing or rusted/worn rivets.

These trucks were built pretty tuff not like some of the new junk. I have had 3/4 lift of lumber in the box of my truck with add a leafs and a few more leafs then stock on a 10 bolt rear end and it never came apart lol only did that once but they are tuff.

 

[columnshift]

Well if you stuff a 14 bolt FF rear end in you don't have to worry about axle failure due to stress, That's what they were made for. so then its just making sure your suspension is up to eh task, next in line is to ensure you have no weak spots in your frame like rusted out areas and that all brackets cross members are properly secured like no missing or rusted/worn rivets.

These trucks were built pretty tuff not like some of the new junk. I have had 3/4 lift of lumber in the box of my truck with add a leafs and a few more leafs then stock on a 10 bolt rear end and it never came apart lol only did that once but they are tuff.

Tire, suspension, and axle upgrades are all planned anyways. I'm just curious at what point I should be concerned or/and interested in either frame or frame-to-body attachment points. (since I think that's all there's left to upgrade? ) And i'm wondering what would be different about them. At what years do you think the new stuff is junk/worse?

For instance according to here http://www.dieselpowermag.com/tech/chevy/1203dp_reinforcing_our_1991_suburbans_frame/ , the steering box attachment area ALWAYS cracks and it's a weak point so they make an upgrade piece of steel for people to put just there to strengthen it against cracking. I'm curious if anyone has any suggestions beyond what the magazine suggests for areas that might be affected by 'running heavy', or off road pounding, or any other flat out abuse. Where does it crack or show damage if abused? Etc. (the article also says "will never be as strong as a modern truck frame" but i'm curious why they'd think that)

Mostly though i'm curious where a 1 ton pickup would be different in terms of frame (is it thicker? taller? more crossmembers?), body-to-frame connections and similar. My expected ideal loads are more in line with probably a 1 ton crew cab (no idea what the ratings are for that, just more than 3/4 level.. any idea?) I just vastly prefer an enclosed suburban body is all with the choice of remove rear seats for 8ft sheet hauling or keep it for people hauling... I cant park a duallie in my garage else i'd be tempted. Yet if there were areas that even a 1 ton shows cracks at i'd like to reinforce them.

Frame boxing, adding additional crossmembers, reinforcing certain mounting points, adding additional frame-to-body connections somewhere, i'm ears for anything suggested. I don't want to add weight for weights sake though or where its pointless or not scientific. Mostly hoping anyone commenting has seen some 'damaged' frames not including car accidents and can say where the weak points were, to try reinforcing those places if there is a pattern.

 

[MadOgre]

I would definitely do the steering box bolt in brace( if your frame is not cracked there, if it is the weld in brace is what you need ) and an after market engine cross member. That cross member was upgraded in 82 i think. They always seem to crack on the passenger side by the engine mount. in 82-84 they put an extra brace there, and it never happened again.

The actual frame mounts for the cab are plenty strong. I would look at possibly reinforcing the body in these areas if you are concerned.

 

[columnshift]

Just to followup realizing there were a few things I missed before...

That Suburban bodied C60 is cool as hell and I might very well consider that. Though a 1 ton range is more what i'm looking for. 1/2 ton suburbans are more common than 3/4 ton ones, I figure if i'm considering a frame swap ANYWAYS why not bump it a bit.


To kleedus, i've seen suburban cargo ratings (not tow, cargo = inside) up to 3200lbs or so, I would like closer to the 5000lbs i've seen in one ton vehicles even if I don't load it that heavy, because running old stuff at it's maximum limits tends to break it. I like overengineering for longevity.

Yes to the diesel engine swap, heavier transmission and huge fuel tank additions but there are other heavy opportunistic loads that have to be taken as cargo and not towed often enough that i'd like 1 ton running gear if feasible. Though i suppose there's no 1 ton frame matching the wheelbase of the Suburban without cutting and welding back together. If I did cut and weld back together I wonder if that would be all that was needed for an instant upgrade - start with a 1 ton, shorten wheelbase, and plop even a more common 1/2 ton Suburban body on it. Or if mounting points of the 1/2 ton body or something will then become a weak point.


Any other suggestions of where to find a canononical list of differences if not here?

 

[HotRodPC]

I'm just jumping in here. Read most, but skimmed some soooo....

Am I understanding, all these questions are based on you wanting to tow 2700 pounds? As in 1 ton + 700 pounds? That's actually fairly easy to do with a standard as is OEM 3/4 ton Suburban. I've towed a 3/4 ton Suburban on a trailer that weighed at least 1000, so you might just call that 4000lbs for the Burb and a 1000lbs for the trailer, that's 5000lbs and I don't suggest this, but that was even without the trailer brakes set up. Yes, I was very careful cuz it didn't stop real well. Towing truck was a 3/4 ton C6P truck with an OEM bone stock 454, Turbo 400 and 3.21 rear gear.

I'd say be more concerned about having trailer brakes working properly and your weight balanced properly on the trailer so it's not all tongue weight. Let the trailer carry some weight, that's what it's for.

3.73 or 4.10 rear gears should pull 2700lbs just fine. Of course 4.10's would be better but 3.73 would work OK. I had ***** wagon 3.21's towing this load. I was wishing I had 3.73's or 4.10's though. A slight grade and the motor started bogging and feeling the weight.

 

[HotRodPC]

Ohhh and the 200 gallon fuel capacity. Nawww, I wouldn't bother. You should have 40 gallons in a Burb as it is. Remember the weight of fuel and the added tank. What is it? 8lbs or so for a gallon of gas? 200 gallons of fuel is going to be counter productive and hurt your mpg with that additional 1600lbs of fuel + tank weight. Even if 8mpg towing, that's 320 miles a tank or better safe than sorry, call it 300 miles, at 70mph if you're going that fast towing, that's 4 hours for 280 miles. It won't hurt to stop for a leg stretch and piss anyway every 4 hours and fill up. Then also add the safety factor and also consider evaporation with all that fuel sloshing around. Summed up, IMO, 40 gallons is enough as it is.

 

[CSFJ]

Aren't the pick-up frames different from the burb frames also?