Building a truck for towing 10k pounds

[Road King]

Hi guys, I have had a few hotrods, motorcycles, classic cars and trucks over the years and really enjoy them. Problem is I'm just too busy to use them, one reason is I'm usually hauling or towing something. So I have this idea to build an older truck (67-72) setup for towing larger loads. I often haul a 18' equipment trailer with a Bobcat skid steer or a mini excavator. Trailer weighs 3-4000 lbs and equipment 6-9000 lbs so total load can be close to 12k at times. I haul this around with my newer 1 ton diesel but I'm thinking of trying to mix a little business with pleasure so to speak...?

So my ideas for the truck so far are taking a 67-72 c20, c30, k20, k30 and dropping in a more modern engine and transmission and updating the axle, brake, and suspension. Maybe a Vortec 6.0 with a tow/haul mode tranny. I have also had the idea of taking a newer truck like a 96-2004 and taking the body off and putting an older body on. I feel like going this route I could go with a diesel a little easier.

I want the truck to be safe and handle the load without stressing the truck or me the driver. I want the mechanical side of it to be 10 out of 10 without issues. The cosmetics I'm not as worried about but would like it to be sharp or have that clean, well cared for, original look to it. It also needs to be fairly comfortable and a good driving truck as I would be spending a lot of time and miles in it.

What are your guys's thoughts? Am I crazy? Has anyone done this before? What kind of budget would I need to have this built? Know of anyone in the Madison WI area that would be good at a project like this? Thanks for looking, I'm really looking forward to hearing your ideas.

[DANTIP]

I've towed a 7,000# trailer (surge-brakes) with a vintage 1/2-ton '72 many times. If I were contemplating pulling an electric brake trailer, I'd have to be convinced that the trailer brake controller worked well with my vintage truck.

[tsetsaf]

Once in a while no problem but all the time I would look at some of the diesel swaps that people have completed. Use the frame and drivetrain from a late model diesel. These trucks only weigh 4k pounds and the frames do not compare to modern trucks.

[Coley]

If it were me...I'd look for a H.D 3/4ton longhorn. To my recollection they used 1 ton frames....although I would probably add air bags, etc to the rear suspension.
So you would get a nice looking H.duty truck, with some collectability and 'show-ability' with some pretty heavy duty undercarriage.
Now, all that said...even if you do equip it to tow and handle a substantial load (which you certainly can) you won't be able to change the listed GVW ratings or the max. tow rating if you get pulled over of if something happens while towing.
In my opinion these trucks can haul and pull more than their original ratings simply by virtue of modern tire technology.
The original tires for these trucks from that era were usually bias ply tires with about 60% of the load rating of todays trucks and equivalent size tires (15", 16" etc). This, in itself seriously limited what GM (or any manufacture) could designate their trucks to haul.
My two bits.
Coley

[BlacklandCamper]

Ditto on using a modern frame. Unless you really want to do a body off, and restore an original frame while boxing it.

The result would also give you a bit more availability when it comes to parts. Front brake hoses for a 1971 C20 are a PITA to find, but easier if it's a 200X 2500HD. Brakes and axles would be better suited and more up to the task as well.

You can still find modern single cab long bed trucks, so I would go that route.

[Mike C]

Longhorn is a great idea since you get leaf springs already. But This is the kind of project that ideally suits a re-body IMO.

I would look at C30's in the early 80's as donors. single wheel or DRW. The 133 inch wheel base on one of these would be the same as the Longhorn if you wanted a fleet side bed. Good disc brakes and 14 bolt already in place.

A dual rear with a flatbed means all you need is a good donor cab from an earlier truck. K30 would be awesome, but 4x4 are much more expensive than 2x4 so consider that if you don't need four wheel drive.

I have an '86 K30 and have considered this. I would be looking for a cab and chassis truck that has the 14 bolt rear axle. The regular duallys mostly had Dana 70's and are a little wider.

The cab and chassis setup would better fit an early truck and custom build a flatbed to match/fit. My K30 has a 10,000 GVWR. And somebody before me used to pull something that used a 3" ball....

[Stocker]

Start with something like this... upgrade the powertrain to suit. http://67-72chevytrucks.com/vboard/s...d.php?t=656749

[BlacklandCamper]

You could also try to find a Custom Camper. Those have leaves and a one ton frame as well.

[Road King]

Thanks for the reply guys, nice looking truck btw.

I'm not that familiar with the long horn?

So it sounds as though finding a newer truck and doing a rebody would be a better bet. The 6.0 vortec with it's 4 speed auto is a pretty solid drivetrain, maybe go with the big block 8.1, or duramax but I have to admit after having all the diesels I have become a Cummins fan. I would also prefer a 1 ton single rear wheel. So maybe finding a 99-04 clean frame, lower mileage 3500 would be the way to go. At least the mechanics would already be setup.

So how would the vin and gvw work on putting an older body on a newer frame? I would assume you would get the frame gvw?

I can obviously put a price on the newer truck but what would it cost me to have a shop do the rebody? I would guess around 3-5k for the body, 3-5k for install, and 4-5k for paint? Does that sound about right? I know things never end up being as cheap as you think but it's nice to start with an idea at least.

[1972RedNeck]

I have done a lot of measuring and it seems that a '67 to '72 Chevy cab would be close to bolting up to all of the body mounts on a first generation Dodge Cummins. Forward to back they were almost exact but side ways was a little off I think - I don't really remember though.

Just a thought because towing with a V8 sucks - both literally and figuratively.

[Road King]

Your right, towing with gas is not ideal but not the end of the world if towing only in shorter trips, interstate it gets a bit tough on them.

That is a good idea on a first gen Cummins since the body's are complete junk most of the time anyway. A 67-72 4x4 with a cummins would definitely turn some heads, that would be quite the sight and sound combo.

[Userone]

that show Trucks did something similar to this on their show awhile back. but they used an old f#rd body on a newer d#dge frame with a cummins diesel. I'm sure their website has all the episodes to watch to see whats involved.

[low&slow]

I'm going to follow in on this as I have been wondering about doing some occasional towing. Not as much as the OP wants to do, but maybe a flatbed or enclosed car trailer with either an old truck or old car on it say from Idaho to Wyoming to Texas and back.

Would heavy duty airbags or even helper bags be something ideal to have for towing either heavy loads short distances or light loads long distances?

[RedRoad]

Here is a thread with an early cab on mid 80s one ton 4x4 frame

[Road King]

Does anyone know of a good shop within 100 miles or so of Madison WI to take on a project like this? Thanks

[Aruba1]

My C20 towed between 9-10k just fine but it was a bit hard slowing down due to the trailer brakes not being connected.

[davepl]

Originally Posted by Coley

If it were me...I'd look for a H.D 3/4ton longhorn. To my recollection they used 1 ton frames....although I would probably add air bags, etc to the rear suspension.

That's what I've heard as well. A friend of mine trailered his racecar all around the country with his '70 Longhorn. He swapped in a 502 I believe but the truck itself did just fine.

The Longhorn gives you the additional wheelbase for stability and the one-ton frame even in the 3/4 ton versions. Of course you can also get them in one-ton, but they're not all that different from the 3/4 ton because they all use the one-ton frame.

[TwoFiftyShifter]

So you already have a one ton diesel, I say just get a 67-72 20 or 30 series with some 4.11 gears and maybe a fresh 454 if it has an old small block. The brakes were pretty good on the heavy duty trucks.

[dirtwork]

I have towed 10k pounds with my 72 C30 several times. My truck is a dual wheel chassis with a flatbed. Powertrain in 350 with SM465 trans. I have gone through all the brakes since I have owned it, and with a good brake controller it does fine. Its not a race rocket but tows pretty nice.

Modern pickup trucks have certainly come a long way in towing capacity compared to these old trucks. Towing around 10K with a 1 ton dually truck has always been within the realm of their purposes. A common practice in the construction trades and farming.

If you plan to tow frequently then I too would say a big block truck would be optimal, but for occasional use a small block with 4 speed will do fine on local runs.

[Aruba1]

Mine has a overhauled 5.3L (headers and LS1 intake), NV4500, 1989 C3500 front/rear brakes, C3500 dually rear-end, supersprings in the back, aluminum radiator, flatbed with a liftgate and rides on 19.5s. Next items to install are hydroboost, p/s and onboard airbags for the rear suspension. So far they have been collecting dust in the garage.

[69chevytrucker]

putting a body on a new frame is the easy part 67-72 cab mounting points are in the best spot for modifying i took a 69 and put it on a 83 5k blazer frame and i have seen on here someone did it with a 2000 tahoe if you are willing to go 4x4 and lifting the body 3 inch you can mod the mounting with ease.




i had to shorten my box 30 inches or so but the rest was pretty easy.

[davischevy]

The GVW of the truck and trailer pictured is a little over eleven thousand#. this truck has a 700R4, but if the 4L80 would be much better under these loads.

This Longhorn has the factory big block and I am considering a turbo charger to increase the HP.

I have some 6.0 late model GM trucks and I am not impressed towing 10,000 lb loads with them.

[jocko]

Originally Posted by BlacklandCamper

You could also try to find a Custom Camper. Those have leaves and a one ton frame as well.

Custom Camper did not give you either of these. You could have coils or leafs and the standard lwb (127") C20 had a 3/4 ton frame.

[swamp rat]

This guy hangs around here a bit, from Washington state but does the same kinda stuff

http://www.rtechfabrications.com/

There has also been a number of diesel conversion build threads

[Ken B]

Here is my C30 1 ton Longhorn. It is factory rated for 9000 pounds. My truck has a 350 with a 4 speed and 410 gear ratio., leaf springs with factory helper. It can haul anything, its the stopping that can get a little sketchy. (mine has drum brakes..) Definitely make sure you have power disc brakes... I'm happy to see someone that wants to use these trucks for what they were meant for, work! There was a really nice Longhorn on Ebay last week that was near me in CT. I never did see what it sold for...