73 - 91 chevy frames

I want to build a 73 - 90 chevy (GMC) crew cab work truck for dependabuility. I want to use the heaviest frame i can find as i am going to use it some for a wrecker truck. I would like to use a 1 ton 4x4 crew cab frame but am having problems finding one localy.

 I am receiving conflicting opinions from the local body shops and the local salvage yards. Is the 3/4 ton crew cab the same as a 1 Ton, at least in some years? Some believe it is the same others believe it is taller in places and yet others believe the 1 Ton frame is narrower. (This could depend on whether it is a duely or a cab and chassis) Is the cab and chassis frame heavier? 

I have located several 1 Ton two wheel drive frame and cabs. If i change the front cross member and add spring perches would it be the same frame? (I realize the frame will have to be drilled to add the rear spring mounts and do have the equipment to do most any procedure needed) Further having different cross members up front is the steering box the same?

I would welcome any advice or tech input as to which year or frame would be recomended. Thanks William Felts Dodge City KS

2500 and 3500 CC's use the same frame in that body style truck. You are not giving up anything by using a 2500 frame. Even new Silverado 2500HD and 3500 SRW's use the same frame too.

i also heard that some one ton frames are narrower thatn the 3/4 ton ones!
as to 4WD conversion, the steeringbox ist different and you ll need crossmembers for the trany-t-case combo, plus a new front axle, best bet a dana 60. that could be hard to find!
the only way you could make the 2WD steering box work with the 4WD conversion would be a cross over steering set up as you need the 2WD boxx for that. but i assume you won´t use a lift on the truck, and if you don´t there won´t be enough room for the crossover steering. so either you swap steering boxes too or you lift the truck and run crossover steering!
will you use your truck with single or dual rear wheels?  

Do not rule out a Dana 50 that are not that hard to find and that are often overlooked (used in a lot of Fords) it is closer to a 60 in overall strength than it is  to a 44 in weight capacity and axle shaft strength as it is only about 10% weaker than a 60 but about 30% stronger than a 44.

you might also try searching for info at www.67-72chevytrucks.com they have a VERY active 73-87 board and a good 4x4 forum...  

Thanks all  I will be running a dana 60 out of a 83 chevy 1Ton. I want to have my springs rearched and milatery wrapped at atlas spring as shown in a past issue. I expect a 2 inch lift with the extra thickness and rearching. I will likely use a 350 with a sm465 or nv4500 if one can be found reasonably priced. I have been learing about frame strengthing techniques by looking under ton dump rucks and box vans locally. I will likely use a special 1/4 plate bent to a 90 and run the length of the frame on the outside from the cab to the rear spring mounts. Inside the frame I will use 1/4 fishplate bolted through to the outside plate. Is this the weakest areas needing reinforcing? I think i will want to add some frame crossmembers for strength have any ideas where the should be located? Im guessing this will save stress to my body and frame at a cost of axle articulation as the frame will have less flex???. I will be using a wheel lift from time to time.  As for the rear I have 3 Corp 14 bolt axles. One has a detroit locker and home made disk brakes. I also have one each of the duelly and cab and chassis axles(i think as the spring mounts are spaced different in relation to the drums) . I do want to run duels when running the wrecker. The t case will be a 205. I need to do a little more studying to make sure all the components I acumulate will couple up. Maybe best to find a already matched combo. Any other considerations? William

I would box the frame as it would give you the most added strength with least added weight and cost. Use same size metal as frame rails and it will increas strength by about 50 to 75%. (more than you will ever need)

while you are beefing up the frame, the frame area where the steering box mounts is prone to cracking.

Very true, that is a area that needs a beaf up plate added to it. A 3/16 inch plate sandwiched to it and extended beyond the mount area should do the trick.

Yes I started having some cracking there on my 77 Blazer and bough a prefabed kit which was welded to both sides of the frame where the steering box mounts. I will automaticly do this to any chevy truck I buy. I believe I have seen a couple of companies who make these do you have an opinion as to which brand would be better in either design or fit?  

No aftermarket option I favor on this. I have always been one to make my own for this kind of stuff. Do not get over zealous with plate size because you could move stress to another area to crack. The trick is to beef it up and spread the load evenly henuce using same thickness as frame rail. I would place a small plate inside rail that covers mounnting holes and a larger/loneger one on outside uder box so the stress in "stepped" into frame smoothly.