2wd to 4wd.....just curious

[FLYNAVY30]

Just curious what it takes to change a 3/4 ton 2wd to 4wd, and if you were to do it, what would you upgrade/change from factory in the process? Are there any differences in the 3/4 ton frame between the 2wd and 4wd trucks?

This isn't anything I would be doing in the immediate future, but something I'd consider when I pull the body off the frame in a few years to address the rust in the truck.

Thanks!

[vectorit]

Lots of work, and I'd be looking to do a chassis swap instead.
If your current situation is rear coils, they will not be all that great in a solid front axle 4x4 configuration.

Haven't seen anything on the frame that makes the two different, just body mounts and suspension parts.

[FLYNAVY30]

Originally Posted by vectorit

Lots of work, and I'd be looking to do a chassis swap instead.
If your current situation is rear coils, they will not be all that great in a solid front axle 4x4 configuration.

Thanks Chris, that's kind of what I figured. I imagine if you're going to go that far, it might be worth considering an aftermarket chassis.....depending on where you are on the time vs. money scale.

[vectorit]

I'd just keep your eyes open for a 4x4 67-72 roller burb.
One where the front clip, engine, trans is gone and the tub is rotten.
Hopefully with a title, then pop the rusty tub off and send it off to recyclers.
Rebuild, clean the new old 4x4 chassis and then swap it under your nice 2wd burb.

[FLYNAVY30]

fair enough

[randy500]

Use a long bed truck 4wd chassis, same as suburban when you add suburban body mount brackets, easy peasy

[vectorit]

Swapping a LWB PU frame is doable, but it is not a direct replacement.
It will need fabrication to work, plus the burb frame is longer in the back since the rear bumper mounts to the frame unlike the PU's.

[franken]

Many trucks use swingarms, while 4x4s use leaf springs. I imagine you can use either but check the diff ratios...

[Madkidd007]

So let me jump in this and first I’m gonna be the guy to argue everyone that says it’s too much work to convert a frame, after all swapping frames requires a ton of stuff to be moved. The real question that should be asked is do you just want to go 4wd or go with a big lift at the same time? I’ll keep my mouth shut till you reply to that question as to keep confusion down. But I ran a 2wd could spring LWB chassis setup as 4wd on 37s with no tire rub and glad I did because the truck is now 2wd again and took just half a day to put back

[FLYNAVY30]

No, if I were to eventually convert my truck to 4wd, it would not be to put a big lift and huge tires on it

[Madkidd007]

Originally Posted by FLYNAVY30

No, if I were to eventually convert my truck to 4wd, it would not be to put a big lift and huge tires on it

Well I’m that case need another chassis because of the rear coil spring setup. I’ve flipped the axle under the trailing arms but just that alone gives you about 6.5” of lift from 2wd height so for stock height 4wd that’s too much. What randy said is something to keep in mind about a truck chassis, I may be wrong but I think only 72 the rear bumper bolted directly to the frame and the older models used brackets

[HO455]

It is a long ways away (unless you can swing a transfer to Whidbey Island) but a prime candidate.

https://seattle.craigslist.org/tac/p...942130058.html

[FLYNAVY30]

yea, that would be a good candidate....unfortunately, this project is still a few years out. That being said, its pretty apparent that a full chassis swap is probably the easiest way to go.

[HO455]

When your ready reach out to richard2717. He is has been known to part out Burbans from time to time. I believe he is in Maryland which is somewhat closer. And he is a real nice guy to boot.

[FLYNAVY30]

will do, thanks!

[FLYNAVY30]

In doing a little more research into a chassis swap, does anyone know if the '73 and later K20 Suburban chassis will work under the '67-'72 Suburban body? If so, how much work does it take to adapt?

[mcmlxix]

No Limit Engineering out of Tennessee can build you a fully boxed chassis to what ever specs you want.

If it was me (and can't afford a new chassis) I would do a B52 swap on the front from www.diy4x.com and find someone to build beefier rear trailing arms and use go 4 link in the rear...

[FLYNAVY30]

Originally Posted by mcmlxix

No Limit Engineering out of Tennessee can build you a fully boxed chassis to what ever specs you want.

If it was me (and can't afford a new chassis) I would do a B52 swap on the front from www.diy4x.com and find someone to build beefier rear trailing arms and use go 4 link in the rear...

Interesting....

Its fully how all of these shops advertise aftermarket, Pro-Touring style frames, but nobody is advertising aftermarket frames optimized for 4x4 applications.

I'd be curious to see what they charge for a fully boxed frame that is essentially a stiffer version of the factory frame, that would accept all of the factory body and suspension mounting points.

[Mike C]

If you want 4 wheel drive without a lift and tires over 33" in height, I would also keep the trailing arm rear and do some conversion in the front. Even if it just meant the factory 4x4 setup parts from a donor. Would be a super cool beach cruiser.

Would take some creative drive-shaft fab, a donor front axle and steering box from a 4 wheel drive unless you do cross-over where you can keep the 2x4 box. Trans and t-case. TH400 and 208 from a square body should be pretty cheap. Would be a cool conversion without a ton of new parts.

[mcmlxix]

Since the Suburban is such a long wheelbase, find a divorced NP205 or buy an Atlas transfer case. You could essentially have a 4x4 without changing the drivetrain...

[FLYNAVY30]

Originally Posted by Mike C

If you want 4 wheel drive without a lift and tires over 33" in height, I would also keep the trailing arm rear and do some conversion in the front. Even if it just meant the factory 4x4 setup parts from a donor. Would be a super cool beach cruiser.

Would take some creative drive-shaft fab, a donor front axle and steering box from a 4 wheel drive unless you do cross-over where you can keep the 2x4 box. Trans and t-case. TH400 and 208 from a square body should be pretty cheap. Would be a cool conversion without a ton of new parts.

Yes, not interested in a monster ride height or tires....essentially looking at stock ride height K20 with 33" tires.

What would the advantages/disadvantages of leaving the rear trailing arm set up while converting the front to leaf springs be as far as ride quality and handling....both on and off road?

[FLYNAVY30]

Originally Posted by mcmlxix

Since the Suburban is such a long wheelbase, find a divorced NP205 or buy an Atlas transfer case. You could essentially have a 4x4 without changing the drivetrain...

That would actually make a lot of sense since I already have a built 6.0L LS along with a Gear Star STG II 4L65E.

[HO455]

205s are light and basically bulletproof used to be real cheap but the crawler crowd has decided they are valuable so prices have gone up some. Lots of Ford units out there but they are clocked wrong for our trucks. The Dodge units are set up for the front pumpkin to be on the same side but you may have to use a Dodge crossmember. I don't know this for a fact but something to be aware of. Or build your own crossmember like I did in my 52.

[FLYNAVY30]

good info, thanks!

[Mike C]

The trailing arms ride smoother with their coils than the leafs and they naturally inhibit spring wrap up. You can buy taller rear coils which would let you match height to whatever conversion method you used in the front at least up to a few inches.

I prefer an integral T-case over a non integral, but either work. One interesting thing about the non integral is you can have a longer front shaft and a shorter rear shaft. One of the reasons the 4x4 motor is back so much further than the 2x4 is to get enough length on the front shaft.

If it were mine, I would consider stock HD '73 and up front springs, an 8.5" 10 bolt with 8 lug wheels and either DIY4x4 or '73 spring brackets. The '73 springs are a little longer and should ride a little smoother.

I would also try and find a passenger flat top knuckle and do crossover steering using you factory 2x4 box. Once it was together, pick some new rear springs to match front rid height.

Might make sense to swap a 14 bolt in the rear at the same time if you have an HO52. That would let you run a limited slip. It would be awesome with TrueTracs in both ends

I have some of these parts if you are still considering this when you move to my part of the world.