Swap question.

[truckdrivinsob]

Hey guys i searched but nothing really came up for my question. Here is the deal my buddy's grandpa built a 50 Chevy p/u on a 85 Chevy 1 ton dually chassis. My question is can we swap on some 1/2 ton suspension? I know a lot of stuff interchanges just wasn't sure on 1 ton duallys. Frame swap is an option but a lot of work i don't really want to do.

[truckdrivinsob]

anyone?

[Steve@OldSub.com]

With no more than minor modifications you can swap the IFS. If you check part numbers you find many of the parts are the same and may allow swapping only parts of the suspension.

You're dealing with a frame made of taller and thicker material that will increase the weight of the truck and might complicate using aftermarket parts.

Also your current wheel base might be a bit long.

I'd consider a frame swap and selling the 1-ton stuff.

[raycow]

Originally Posted by Steve@OldSub.com

With no more than minor modifications you can swap the IFS.

Are you saying the 1/2 ton crossmember can be adapted to the 1 ton frame?

Ray

[Steve@OldSub.com]

Originally Posted by raycow

Are you saying the 1/2 ton crossmember can be adapted to the 1 ton frame?

Yes. Spend some time in the parts books, most the IFS parts, not the wear parts, but the IFS crossmember itself and related stuff, is actually the same numbers across 1/2-, 3/4- and 1-ton trucks in any given year.

It could require some mixing and matching of parts but I do believe you could put a 1/2-ton crossmember on a 1-ton pickup.

I also suggested I'd do it different, swapping to the lighter 1/2-ton frame rather than dealing with this conversion.

[truckdrivinsob]

i just want to swap on 1/2 ton arms and such the truck is already built and on the frame. Runs and drives just want it to be lower and ride decent.

[Steve@OldSub.com]

Originally Posted by truckdrivinsob

i just want to swap on 1/2 ton arms and such the truck is already built and on the frame. Runs and drives just want it to be lower and ride decent.

You can approach it that way but be aware that if you are using 1/2-ton springs to support a 1-ton frame your ride and handling may not improve the way you hope.

I don't know the dimensions of the material used on the 1-ton frame off hand, but I do know that the material is generally thicker, the height more and the cross section larger.

You're carrying a lot of weight there. It will affect ride, handling and braking performance. I don't know what your truck actually weighs, maybe in the process of the swap weight was reduced enough to make these non-issues but it is something you should look at and consider.

[truckdrivinsob]

Yeah it will have 2600lb air bags up front and the rear end is being swapped out so the weight has been cut. It also is not a crew cab dually anymore just a 50 Chevy cab and bed with a 454. And there will be no towing or hauling with the truck. It has power brakes already and we will be putting disc's up front. I just want to know if a=1/2 ton suspension will bolt in place of b= 1 ton suspension.

[Steve@OldSub.com]

Originally Posted by truckdrivinsob

we will be putting disc's up front. I just want to know if a=1/2 ton suspension will bolt in place of b= 1 ton suspension.

Does it not have disk now? How old is this frame and suspension? I could have some wrong assumptions about what you're working with.

But again, the major components of the '63 to '87-'91 IFS are basically the same across the various size trucks according to my study of the illustrated parts catalog and the part numbers. If you have a van or motorhome IFS it could be different, but the pickup crossmember has the same part number within a year regardless of C10, C20 or C30 for those years I've checked. I've not looked up every year but did once check a number of them.

Unfortunately I don't have access to that book right now and won't for a couple of months, so I can't just look up numbers and exactly where things are different, but I would expect the differences to start with the wear and adjustable parts.

Things like a-arms and spindles are different between sizes though in those cases I've checked C20 and C30 are the same.

They all had disk brakes starting in 1971 so if yours does not have disk that makes it a pretty early one. While I remain confident you could swap the pieces onto your early crossmember I know there are some differences and the older the crossmember the more there are. You'd be better off with a later crossmember.

The wear parts are said to be cheaper and work better starting in '73. There are only 14 bolts holding that crossmember in place, it might be less work to swap to a later 1/2-ton complete than to remove all the parts to swap from the shafts out. Though if you're replacing the shafts anyway that would not matter.

With your reduced weight and air suspension you may have the ride and handling concerns under control. I'd still want to know the total weight of the vehicle and any likely load and be sure it was less than the rated capacity of the brakes. As you convert it to a 1/2-ton you want to be sure the total weight is less than the GVWR of the 1/2-ton brakes you are relying on.

[truckdrivinsob]

It is a 1985 chevy dually and has discs up front. When i get up there i will lay my eyes on the frame and compare it to my 65 see if its taller thicker and such. Thanks for the info.

[csa daddy]

yes all the 1/2 ton arms will bolt to the ton cross member its no problem unbolt an bolt back up an have an alignment done plus the frame should lay out befor ethe lower a arms on a ton frame but you can z it an cut the bottom of the frame off an put a 2x4 sqare steel in a reweld the bottom an box it if you like if not the whole thing then atleast a couple of spots. i hope this helps

[Steve@OldSub.com]

Originally Posted by csa daddy

yes all the 1/2 ton arms will bolt to the ton cross member its no problem

This sounds like the voice of experience which does trump my parts book based approach. Thanks for the info csa daddy!