Convert a 1500 to a 3500

[aloharovers]

Has this ever been covered before?
What all would be involved in converting a 1/2 ton into a one ton?
I am thinking put a 14 bolt and 1 ton springs under the back, upgrade the front brakes. But is there more? Are the frame actually different?

[More Power]

Grab a dial caliper, crawl under a 1/2-ton pickup, then measure the thickness of the steel used in the C-channel of the rear half of the frame rails. Then compare what you find to the thickness used in a 3/4 or 1-ton. The outside dimensions of the C-frame are the same, but the steel thickness used in the frame rails is heavier in the higher GVW rated pickups.

Jim

[aloharovers]

Makes sense, too bad

[Mark Rinker]

I buy Duramax 2500HDs, add overload Timbren springs and run 285 load range E rubber. No conversion necessary, although your rated GVWR is lower. Many times, used 1-T sell for less than their 3/4 T counterparts. We buy 3/4 T for easier resale.

[aloharovers]

Well that's good to know.
We have a 92 C1500 extended cab that we have owned since new. In 92 I replaced the 5.0 with a 5.7HO crate and also got an Art Carr 700R4 that was built specifically for towing.
The truck has been perfect, except for the recent starter issues. The truck has towed 2 horses, utility trailer or a 24' RV just great. I even towed my Rover on a flat bed from WA to CO when we moved. 7k total weight pulled great, except for the steep hills and the 5mpg
I recently got a low milage 6.2. Been staring at it in my garage and dreaming about maybe sticking it into the 1500 along with a banks kit.

But there are two factors against it, the tow capacity and the lack of 4 doors. We have two little ones now and it really is a PITA trying to get them into their seats in the back. We are looking for a larger camper and I am really interested in a combo camper/Rover hauler so I can attend some events on the East coast with the family.

So knowing that it really isn't practical to try and stick a biger axle and springs under the truck just puts one more vote into the 'new' truck column.

Really would like to get a 4-door, 4x4, 1ton. We are also looking at getting rid of my wifes 2wd SUV and getting her a 4wd. Plan on a diesel for her as well. I wish I could get 03 or 04 Sub and 1ton both with the same engine. Just makes it easier in my opinion to maintain them. But I have a feeling we will end up getting an 02 Excursion with the 7.3psd.

[bmp34]

My dad growing up on the farm told me how they were able to order their half tons with 3/4 or 1 ton tow packages which usually included springs, rear axles, and tires.

[Craig M]

As More Power explained, the frames are smaller, but a lot depends on what you intend to do with a custom 3500. Bumper pull of a trailer, 5th wheel camper, gooseneck trailer or heavily loaded pickup beds, all exert different forces to different areas of the truck and frame. Items on the frame can be stiffended or modified as required for diferent applications. A modified 1500/3500 will probably never be as universally good as an original 3500, but could be built for a specific application. The 5th wheel trailer is the perfect application. The design of the supporting structure of the actual 5th wheel can transfer the loads directly to the frame. The connections points can be very close to the spring shackle ends. With the 3500 springs and hardware allready installed, this could be a very acceptable application.

[wfyehl]

Wouldn't you still have to worry about breaking axles, drive shaft, and /or u-joints in the 1/2T drivetrain? I had a 1981 K10 that I wanted to pull a 12,000lb boat/trailer combo (100 miles one way). I did upgrade the springs to 3/4T springs, but didn't trust the rest of the drivetrain to not break at the worst possible time (pulling boat out of the water). Then, if you change the axles, driveshaft, and u-joints, you have to worry about twisting or bending the frame.

After looking into it, I decided to get my K2500 Sub to take care of that chore. And the whole family fits into it also (no longer need to take two vehicles when launching the boat, or pulling it out of the water).

Bill

[Craig M]

The switch from 1500 to 3500 includes an axle and spring swap. the modified rig will have 3500 axle and brakes. The driveshaft and u-joints connect to the engine and since power is not being modified will work fine.

[wfyehl]

The switch from 1500 to 3500 includes an axle and spring swap. the modified rig will have 3500 axle and brakes. The driveshaft and u-joints connect to the engine and since power is not being modified will work fine.

Wouldn't the ability to actually haul heavier loads put more stress on the driveshaft and ujoints? With my old '81 truck, I was worried that the driveshaft might twist and/or break while trying to pull my 12,000lb boat out of the water. After all, the driveshaft and u-joints are just 1/2T strong. Or am I way off?

Bill

[Colorado Kid]

Wouldn't the ability to actually haul heavier loads put more stress on the driveshaft and ujoints? With my old '81 truck, I was worried that the driveshaft might twist and/or break while trying to pull my 12,000lb boat out of the water. After all, the driveshaft and u-joints are just 1/2T strong. Or am I way off?

Bill

I'd say yes and no. The maximum force that can be applied to the u-joints is a function of the engine torque and transmission and tourque converter multiplication, so it wouldn't be changed. However it may not be the peak loads that wear these parts out, and with a heavier load they'll be under more stress all the time. The driveshaft twisting scenario is definately out, but the U-joints may not hold up to sustained heavy loads (so it fails climbing a long grade instead of a boat ramp.)

[trbankii]

I think that these sort of conversions always comes down to what the actual purpose is for you. Typically you will be cost and time ahead to just go out, sell your 1500, and purchase a 3500 straight up. Same goes with 4x2 to 4x4 conversions.

The questions start when you want something that you just cannot find out there and/or want some sort of challenge to keep you off the streets... Say a DuraMax Suburban, '51 Chevy diesel, or whatever. Or even if you have a real cherry late model truck and can find a fairly cheap donor vehicle.

If the latter speaks to your case somewhat, I'd almost wonder if it would be worth finding a 3500 chassis - frame, axles, etc - and swapping your stuff over to it? Depending on what sort of project you're looking for and all, that might be my route. Then you could sandblast/paint the frame; upgrade bushings, ball joints, whatever; and have a "new" truck when you were done.