differences in 3/4-1/2 ton frames???

[chevelle]

I am wanting to get my 1/2 ton longbed able to haul my trailer, and i am wondering what i would have to change to make it a 3/4 ton? It is already 4.5/ 6 inch drop and will soon be bagged. can i use my drop spindles with 3/4 hubs on the front? Do i just need to add some strength (box frame and add some bars) to the frame to be able to haul? what about the rear would it be easiest to try to find the right year rearend and bolt it up or try to make a new style fit? any advice would be great

[Longhorn Man]

how much does the trailer weigh, and how often/how far would you be hauling it?
The frames are the same between 1/2 ton and 3/4 ton. there's some added braces, and added plate metal to the trailing arms, but the frame as a bare assembly is 99.9% same. (cab mounting points are located lower on a 3/4 ton)

[chevelle]

The trailer is a 24 foot enclosed and i haul race cars with it, a chevelle or a rear engine dragster. I would guess around 5,000 lbs give or take. i travel 20 miles reagularly to race on weekends with the occasional trip to farther race tracks.

[Classic Heartbeat]

The 3/4 ton frames are heavier than the 1/2 ton frames by about .050" and also the rear cab mounts are lower. I do not know anyone who is making 3/4ton drop spindles that keep the wheels 8 lug. There are 3/4ton drop spindles however they require you to change to 5 or 6 lug because they use the 1 1/4" spindle pin. As for the rear end, the easiest thing would be to find one out of another 67-72 3/4 ton truck. If you have rear trailing arms, 73 and newer didn't use them. If you have rear leafs the frames are wider so the spring pearches are farther apart. Lot of other things that need to be addresses, but there isn't enough information in your innitial post to address them. WES

[Classic Heartbeat]

Also looking at what you are going to pull, a 1/2ton is plenty heavy for that. WES

[crakarjax]

The front wheel load will be negligibly heavier when towing anyway. You could do 5 lug on front and 8 on back, but I see a lot of people towing trailers with 5 lugs all around.

[Longhorn Man]

Wes... for YEARS I've been reading that the frames are the same, both on here, and elsewhere. Knowing that you have gutted more trucks than I have even laid eyes on, I had to break out the books.
I flipped to 1969, since it is such a common year for the trucks (record sales) and I found you to be 100% right.
C/10 frames listed as:
39,000-lb test steel; section modulus 2.98
Then, flipping to the 3/4 ton page:
39,000-lb-test steel; section modulus 3.48

Now, I have no idea what section modulus means, but, it tells me enough to say thank you for teaching me something today.

[Classic Heartbeat]

,,, Awwww, so you can teach an old dog something after all. It's a common missconception, because you can bolt on body parts from both 1/2tons & 3/4tons without altering the chassis or parts. I am glad that I was able to school ya today.. WES

[chevelle]

thanks for such a quick reply guys, it was really helpful

[Longhorn Man]

LOL Wes!

[rsavage]

If you notched the frame for the drop, I personally wouldn't use it as a tow vehicle for 5000lbs +. I would be worried about the structural integrity with that kind of load/tongue weight/leverage. 1/2 ton axles will certainly pull that weight, but you will need tires and wheels that can handle the load. I've towed for 35 years 90% of the time with 1/2 ton pickups. Had a 23" Baja that was about 5500 lbs with the trailer and a 4Winns Liberator that was heavier than that before. Currently, I have a 1/2 ton 08 Ram 4 door shortbed with a Coachman truck camper - the camper weighs about 1900 lbs, and I pull a 6 X 10 enclosed trailer with my Harley in it - about another ton, but fairly heavy tongue weight. I wasn't comfortable with the stock 20" aluminum rims and stock tires as I weighed the rig. I bought steel wheels and found some cooper 20" extra load tires that have a rating of 3000 lbs each as compared to the stock Goodyear's 2400. Firestone air bags keep it level. I tow 3500 - 4000 miles a year, most on one trip south and back to get some sun and riding in. Maybe I overdo it, but I don't want something breaking at 70mph. Pulling a trailer with a lowered vehicle also presents clearance problems on driveway/parking lot approaches -just my 2cents

[Longhorn Man]

just to add to the good info, I hope you have the proper hitch set up. I see too many people towing these kinds of loads with a step bumper hitch... which is usually just a class one. You'll need a class 4 or 5 for something like this.
I totally agree with the C notch comment. Even if you boxed it in, I wouldn't want to do it on a regular basis.

[crakarjax]

Originally Posted by rsavage

If you notched the frame for the drop, I personally wouldn't use it as a tow vehicle for 5000lbs +.

I have heard members state specifically that a notch does NOT degrade the frame's structural integrity. I'm not a structural engineer, but if we have any on here perhaps they can chime in?

[MESS-HALL]

Cool. I had been told that the only differences where in differential, suspension and # of lugs. Thanx.

[Longhorn Man]

Originally Posted by crakarjax

I have heard members state specifically that a notch does NOT degrade the frame's structural integrity. I'm not a structural engineer, but if we have any on here perhaps they can chime in?

While I am not a structural engineer either, I can't see how that could be true.

[chevelle]

I have pretty much decided just to get another truck. I'll drive mine i have now as a daily driver(which i already do) and then maybe look for a 67-72 1 ton dually for towing duty. so if anyone knows where the 1-tons are hiding let me know lol.

[MESS-HALL]

Originally Posted by chevelle

I have pretty much decided just to get another truck. I'll drive mine i have now as a daily driver(which i already do) and then maybe look for a 67-72 1 ton dually for towing duty. so if anyone knows where the 1-tons are hiding let me know lol.

........or maybe just a 3/4 ton.

oh........and I have seen several great deals on 1 tons in the past couple months. CL>

[johndawelder]

A 3/4 ton suburban would be the cats ars for towing a trailor & load you described.I towed a 18 ' car trailor for years with mine.Never any issues with it.It had a BB so there was plenty of power.

[chevelle]

Yeah a suburban would be perfect for what i do, i could haul the race car and the family but i would settle for a 3/4 ton. time to start saving money and looking for a new tow pig!!!

[crakarjax]

Originally Posted by Longhorn Man

While I am not a structural engineer either, I can't see how that could be true.

I'm thinking that *as long as you box the inside of the notch* then you could notch up to half the frame height and still have the same amount of metal supporting the weight on the end of your frame. Without boxing it, I'd agree that it would be weaker. I'm assuming that a C-beam of height X is as strong as a square tube of size X/2.

[jrb71c20]

I just put my 71 3/4 ton up on craigslist today. Sad-sad day, if I wouldn't had to come in to work, I'd be face down in a bottle right now. But, hookin a trailer up to mine right now would see the carb blow up and the motor drop a nasty F bomb on you...lol

[1970CustomC10350]

I've never used one but, I've seen alot of guys running weight distributing set-ups. I haul with a 1 ton Dodge (sorry) and I've thought about trying one out. The dually does well as for side-side and stability and it also has plenty of suspensinon but, I thought it might help during panic stop type situations. Also most hitches have higher weight ratings when using weight distributing set-ups.

[thelonerife]

theres a 71 car hauler on ebay now. (red)