is it possible to switch a 1986 Suburban from 2wd to 4wd without too much modifications. I am using a 350 with a 700r4 trany. I don't know what my gear ratio is but if someone has an idea of what ratio i should use it would be appreciated. thanks.
Anything is possible with enough money. I don't think it'd be worth your time or money though. Just off the top of my head, you would have to fabricate the front mounts for the suspension, you'd need the whole front end, new drive lines front and rear, I'm not sure about the tail shaft on the tranny, but probably that, a transfer case, new crossmember, you'd have to tear the interior out and put a new hump in, then you'd have to set up your steering and brakes again. It would be a HUGE project.
2wd & 4x4 frames are different - the 4 wheel drive stuff doesn't just "bolt on" to the same frame - so your best bet here would be to either look for a 4x4 suburban and sell the 2wd, or plan on a frame/body swap, depending on which is in better shape.
IMO, you'll be better off keeping your present truck intact and looking to buy one that's 4x4.
I agree with Rob. I know of places that do conversions and they all say swapping the frame is easier. A 4wd frame is built differently then a 2wd. I think buying the whole truck would be better unless it is some sort of restormod or specialty vehicle.
Another difference: the rear spring shackles are mounted lower on the 4x4 frame (for increased ride height) meaning that even if you could adapt the front leaf springs/solid axle to the 2wd frame, you'd still have to install lift blocks to get the back end up to the right height.
I had thought of doing the same thing to my '75 dually (C-35 to K-35 conversion) and decided that I'd either build up a 4x4 frame & axles, then swap the cab & deck, or simply get another truck and leave the 2wd alone. I'm starting to lean more & more towards eventually just getting a 4x4 pickup and keeping the dually the way it is - but that's down the road ways: sunk a few $$$ into a different toy this year........
CT18 - I'm thinking the same way, even though I have all the components in my shop to build the 4x4 frame I find I'm not as "into" building trucks as I was several years ago. (Like Bruce posted, ONE wheel drive is what I'm gettin' into! )
First thing will be to see how this winter goes plowing-wise. Future plan is for a newer plow truck, but I'll keep the 'ol '75 as a backup. Since it's also the first wheels I ever owned, I plan on keeping it around for a long time anyway!
If you have time and patients GO for it. I've done one,C-30 to K-30. A good ruler and some know how you'll have a experience to remember. It took my kid and me about 2 weeks of evenings to strip a k- 2500 GMC and to strip my C-30 down and to reassemble the whole mess. Yes my 1 ton has a 3/4 ton axel in it for now but will change after the winter. I bolt the whole mess in with grade 8's 7/16, then welded the front hangers in place to make sure of no future problems. Check chucks Chevy truck page and print out the frame specs. I study them and check reference points.With careful measurements no problems. The only difference in frames is 1" height difference in the front axel hump. I used 4 leaf springs to get around this. Make sure to center your steering box or you might freek out like me. The steering arm was hitting the spring. The truck goes straight and handles good. Oh don't forget the engine cradle or the other net things that go with a 4 wheeldrive