Author Topic: 86 3/4 Ton 2wd Suspension in a 79 1/2 ton 2wd truck  (Read 8488 times)

Offline Torque454

  • Newbie
  • Posts: 33
86 3/4 Ton 2wd Suspension in a 79 1/2 ton 2wd truck
« on: December 27, 2009, 07:18:57 pm »
I bought a complete 86 3/4 ton frame a couple weeks ago and have removed the entire front suspension, including the crossmember from it as well as the rear springs, rear axle, and sway bar.

I believe everything will bolt up, but i'm not sure. My rear springs are fine. They are 7 leaf i beleive and the springs on the 3/4 ton are 8 leafs. I don't need to change them, but if they will fit, i'll change them and install new bushings as well.

Next, Will the front  suspension (control arms and spindles) bolt directly in place of the suspension on my truck? It all looks like it should but I dont want to tear it all apart and find out that i'm wrong. The frame on the 3/4 ton seems to be about a 1/4 or 1/2 inch taller in the front than on the 1/2 ton but the holes i think are all in the same spot. Should I (if i can) bolt in the crossmember from the 3/4 ton or just use the 1/2 ton crossmember?

I removed the sway bar and brackets from the 3/4ton and i know that will bolt up. Basically I am wanting to end up with a complete 3/4 ton suspension on my 1/2 ton truck. It will be used for towing, but nothing super heavy. Its not like i'll be hauling a 30 ft cattle trailer loaded to the max with cattle. I know i'm going overboard with everything but I want to be able to tow anything i would ever need and do it comfortably and safely.  The truck will have a 454 and a TH400 transmission. The axle is a 14 bolt full floater with 4.10s. Not posi to my knowledge but one of these days i'll install one.

I'm pretty convinced everything will bolt up just fine but figured I would ask. I think this truck will be an awesome tow rig. Eventually Id like to install a 700R4 built to the max with a temp gauge to keep an eye on stuff (i know not to tow in OD, but with 4.10s an OD is really needed for around town and hwy driving with no load)

Offline choptop

  • Senior Member
  • ****
  • Posts: 2476
  • Extended cab fanatic
    • conversiontrucks
Re: 86 3/4 Ton 2wd Suspension in a 79 1/2 ton 2wd truck
« Reply #1 on: December 27, 2009, 09:29:00 pm »
Is there anything wrong with the 3/4 ton frame. If its good, use the entire frame and just swap the body/ drivetrain over. It will be easier and will be a better tow rig because of the heavier frame. To me a 1/2 ton with 3/4 ton front and rear assemblies is just a heavier halfton. it will put you in the middle and wont be any more benefit.
76 C10 Choptop,76 C10 Swb
85 C10, 85 K10, 85 K20,86 C10,86 K10 (all extended cabs)
86 C30 extended crewcab

Offline Torque454

  • Newbie
  • Posts: 33
Re: 86 3/4 Ton 2wd Suspension in a 79 1/2 ton 2wd truck
« Reply #2 on: December 27, 2009, 09:47:20 pm »
Theres nothing wrong with the frame but I don't have a way of lifting my body off one frame and onto the other. I also don't really have the time. The city is after me to get this truck going. Ive got about 3 weeks and i've already got my work cut out for me. Lucky for me i've already got the truck converted to automatic from manual trans and about all i have left to do is install the engine, change the rear end (easy) and install the driveshaft. I wont be changing over the front end until the truck is legal, the city is off my back and a fence is put up. If i meet the deadline, the city will be taken care of in 3 weeks (and the truck will be legal) but the fence wont be up for a few months at most probably.

This frame has to be gone by the end of the 3 weeks and i'm not sure where else to put it so it'll probably have to go to the scrap yard. Otherwise i'd love to put my body on that frame.

If i can find a place to store the frame at, i might save it.

Anyways, the frames APPEAR to be the same thickness (ill have to check it with a mic i guess) its just that one frame is a little taller than the other. I don't know if that effects strength or not.

Offline Captkaos

  • OWNER and Administrator
  • Administrator
  • Senior Member
  • *****
  • Posts: 18454
    • http://www.73-87chevytrucks.com
Re: 86 3/4 Ton 2wd Suspension in a 79 1/2 ton 2wd truck
« Reply #3 on: December 28, 2009, 09:59:57 am »
Everything will swap, but the frame is taller and stronger on the 3/4T.

Offline Torque454

  • Newbie
  • Posts: 33
Re: 86 3/4 Ton 2wd Suspension in a 79 1/2 ton 2wd truck
« Reply #4 on: December 28, 2009, 01:23:01 pm »
Thanks. Thats what I thought. The main reason I am adding the front suspension from the 3/4 ton to my 1/2 ton is so that I have 8 lugs all the way around (all the tires and wheels will match). Its not so much for the towing and weight carrying benefit. Plus the price was right, I got everything for $100 including the 14 bolt full floating axle with 4.10 gears and driveshaft which were the main things I was after.

The 12 bolt axle will hold the 454, but the 3.08 ratio sucks for towing. I got everything for less than a set of gears for the 12 bolt and thats a bunch of extras. (sway bar, extra springs, front suspension, etc)

However the big brakes and the stronger suspension will be nice. The 3/4 ton suspension doesnt appear to have large rubber bushings that support all the weight on the control arms like the 1/2 ton suspension has. That should make it a more stable and less sloppy to drive.