Early 70's tow suburban

[Buckthetruck]

Thanks for the info, everyone. It is something I really want to do, but I need to consider all factors of an older tow vehicle. It would look great (but need work to look that way most likely), should have plenty of power that could also be updated if I want, and I would need to put money into it considering safety both in handling and simple things like head rests and seat belts. This all gives me plenty to think about.

[Buckthetruck]

So is there any extra concern for safety? Upgrading the suspension, brakes, maybe interior seats will do a lot, but is there concern for the additional upgrades that can never be retrofitted? I REALLY want to go with a vintage tow vehicle, but I have some struggles with it and my family riding in it.

[vectorit]

With out doing a chassis swap from a newer truck, so that you can get the modern brakes and suspension.

The thing I would focus on the most is the brakes.
If you go 3/4ton, you can upgrade to a 14 bolt full floating axle. These axles have giant drum brakes on them.
For the front brakes, if two wheel drive you could upgrade the size of the discs and new calipers. But you may run into issues with wheel diameter if you want to keep the stock looking steel wheels.

Interior wise, you can install shoulder harness seat belt on all three benches. Minus the seating position next to the 3rd door.

Old cars/trucks don't have all of the modern safety as a new vehicle, since they are running what was considered safe designs of the time. Retrofitting modern safety equipment into a classic is a whole costly project in itself.

I know in my 1968 Suburban, I only drive it at 1968 performance today. Meaning I do not travel faster than 65 MPH, and I keep a very large buffer between me and other cars.

[BK72BURB_3/4Ton4x4]

How funny, was just telling my wife we need to find a vintage Airstream to tow behind the Suburban :-) I echo Chris' prerequisite list for towing:

1. 3/4 ton
2. Leaf spring suspension
3. Air bag over loads
4. Low gears 4.10 is a good all around ratio
5. Updated rear brakes.
6. Full floating axles
7. Manual transmission
8. Engine set up for low end torque
9. Heavy duty engine cooling system
10. Class 3 or 4 hitch, set up for torsion bar system.

I would also add a nice Tekonsha Electronic Brake Control.

We have a couple horses and normally use our 7.3 Diesel Excursion to pull them but I would not hesitate hooking up the Burb (after I upgrade to a Class 3 or 4 hitch and get a larger gas tank!) The 454 in our burb has plenty of low end torque but goes through 12-15 gallons every 100 miles!
Brian

[Alex V.]

"Extra" concern for safety? It depends on how far you want to take the question. Do these vehicles have crumple zones built into the body, side air bags, etc.? Obviously, no. If you want to safely (subjective use of the word) tow your camper and exercise the driving habits of most other people on the road today, then it will require extensive modification of an older Suburban or forgetting about a classic tow vehicle altogether to accomplish it. However, if you can adjust to always leaving extra room in front of the vehicle while moving, knocking 5-10 MPH off your cruising speed (depending on how fast you'd tow with a new vehicle), and understanding what the vehicle's limitations are - which aren't as far from modern trucks as a lot of people think - a classic 'Burb will serve you well in close-to-stock form. And above all, no matter what you're driving, your family's safety depends on your attention and judgment.

[rjsdad]

I have a question. Would a 70 Suburban with a 1 ton rear end with 4.10 gears, a 350 with a sm465 tow an 8000lb trailer? Looking at travel trailers and can't really find much info on the web. Thanks.

[HO455]

Back in the day my dad towed his 1975 vintage 5th wheel with his 73 4x4 F250. It had the 300 six (about 120hp). It would go 58 mph flat out on level ground and dropped to about 45 in 3rd gear on any real hill. He was a logger in northern Idaho and drug that trailer around for years that way. Your stock 350 will be able to better his performance, but you will most likely have difficulties staying at the speed limit on the larger uphill grades. A lot of the "will it tow it" debate has to do with what you are expecting and are willing to put up with. Today we have a large selection of brake system upgrades and trailer brake controllers are way more advanced than back then. Not knowing what tire height your running I can't speak to your ability to cruise at 75 on the interstate, but an overdrive would be a nice addition both for fuel and driveability. With the right additions your Suburban will do a great job towing. Just my two cents worth. Your results may vary.

[rjsdad]

Thank you for your thoughts. I have 33" tires. I know a weak link will be the drum brakes but if/when needed, I could change the fronts out. I'm not concerned with going any faster than posted speed limit. I don't do that now come to think of it. Is there any difference in the frame "beefiness" between series of Suburbans that old?

[Bigdav160]

Years ago, just for laughs, I measured the frame thickness on my 3/4 ton and another 1/2 ton. I seem to remember the difference was only .010".

Also the frames changed very little up to the 1992 model year when GMT400 style came out.

[Alex V.]

Is it a 3/4 ton chassis? For pulling a trailer weighing 8K on long trips, a small block will have to be specifically built for the purpose to hold good speeds without being wide open on any hill. Strictly speaking on the figure of 8,000 weight and the assumption that it'll be over long distances, in terms of near-stock equipment available on our trucks I'd want a big block and good 3/4 ton running gear and stout rear springs or air bags. 4.10's are good general-purpose towing gears when an overdrive transmission or extra tall tires aren't present. Your SM465/4.10/33" tire combo is one of the better ones for towing that much weight at highway speeds (55-65 MPH), but it's a strong 350 or 383 that will move that much weight with much gusto. Disc front brakes are a good idea, as well as trailer brakes unless you have very large (i.e., 1-ton) brakes on the truck. Only one of the trailers I've had hooked up to my '85 C3500 had brakes and I've felt comfortable up to around 9,000 lb. total payload, but those are the big Bendix slide-type front calipers, 13x3.5? rear drums, and hydroboost assist. I'm hesitant to hook up to more than about 3K with my 'Burb's 4-wheel drums in the shape they're in right now. :O

[HO455]

Originally Posted by rjsdad

Thank you for your thoughts. I have 33" tires. I know a weak link will be the drum brakes but if/when needed, I could change the fronts out. I'm not concerned with going any faster than posted speed limit. I don't do that now come to think of it. Is there any difference in the frame "beefiness" between series of Suburbans that old?

From what I have been able gleen from the 1967 truck manual the basic frame on all of the C/K series 10/20/30 are the same, but the factory would rivet various pieces of formed angle iron to the frame to stiffen it up depending on the application. The manual I have doesn't show them but explains the basic ideas with some simple drawings in the frame section. Then it gives a "section modulus" number in the standard equipment listings for comparison. This information may only be in the 1967 manual as it is the first year in the model (common GM practice). It also refers to a frame chart but I have been unable to locate that chart. Hope this helps.

[rjsdad]

Thanks guys.

Hey Alex, I wound be towing this trailer too much. It's going to be a permanent home for me and my boy. I doubt it'll even get out of Oregon for some years to come. I just want to be safe and others to be safe when I'm pulling it.

[Alex V.]

Oh! If it's just moving one-way occasionally, a good 4 bbl. 350 will pull it and other areas of the truck should be of more priority. Maybe not fast, but it'll get the job done and be more practical every other day of the year.

[Average Joe]

8k pounds is ALOT of travel trailer. Is that empty? Figure at least another 1000 pounds when loaded, and thats conservative.
I wouldnt be as concerned about the power as much as the suspension and handeling. Although it will be a slug, just sayin.
How much tongue weight? What kind of WD hitch do you have in mind?
Travel trailers are about the most sway prone trailers. Better consider a Reese Dual Cam or equivalent.
Do you currently have 8 or 10 ply tires? You will be adding weight to the back as well as the front with a WD hitch.
Not trying to disuade you, just passing along lessons i've learned towing a 6k pound trailer. Good luck!

[rjsdad]

It's a 7k lb trailer dry actually. Not sure about the WD hitch type but will definitely be getting one. I know it's a ton of weight and was actually thinking of a 5k trailer, but they're all kinda small for full time purposes. Weekend trips they'd be perfect. Thanks for your honesty fella.

[BK72BURB_3/4Ton4x4]

I have a 1972 26' Airstream Overlander sitting in my yard, babysitting for a friend. Specs say it's 3850 lbs dry. I've been wanting to drag it around with my 1972 K20 Suburban mostly for nostalgic reasons but also curious how well the 4X4 K20, 454 Chevy and 3.73 gears will pull it. I'll be sure to report back with some pics and overall comfort factor once I get a free weekend!

[rjsdad]

Would love to see how it does.