2wd to 4wd.....just curious
 

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!

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

fair enough

Re: 2wd to 4wd.....just curious
 

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

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

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

Re: 2wd to 4wd.....just curious
 

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

Re: 2wd to 4wd.....just curious
 

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

Re: 2wd to 4wd.....just curious
 

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

Re: 2wd to 4wd.....just curious
 

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

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

will do, thanks!

Re: 2wd to 4wd.....just curious
 

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?

Re: 2wd to 4wd.....just curious
 

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...

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

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...

Re: 2wd to 4wd.....just curious
 

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?

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

good info, thanks!

Re: 2wd to 4wd.....just curious
 

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.

Re: 2wd to 4wd.....just curious
 

Also, some states are particular about the partial VIN stamp on the frame matching the body and title.

For the rear, I went with a later model 2004 GMC 2500 with disc brakes and a drum in hat emergency brake. Nice to have 4 wheel disc brakes...

Re: 2wd to 4wd.....just curious
 

Thanks for the info guys....lots to consider. At the moment, its a 3/4 ton C20 with a built 6.0L LS and STG II 4L65E. The rear is the factory Dana 60 and I've already converted to 4 wheels disc brakes....although I do not yet have a parking brake solution.

Re: 2wd to 4wd.....just curious
 

Was it a factory big block truck? Interesting that it is Dana 60 as most small block coil trucks were HO52.

One of the reason I like sticking with the drums. I have an '86 Sub rear in my Jimmy, 8 lug semi-float with the 13" drums. Parking brake works GREAT!

Re: 2wd to 4wd.....just curious
 

Yes, it was a factory C20 with the 402 big block and trailing arms with coil springs in the rear. It does have the "helper" leaf springs for towing.

Re: 2wd to 4wd.....just curious
 

For the quad curious. :lol: I stumbled across these photos of a Dodge 205 set up and thought of this thread. Just food for thought. This particular 205 is set up for a PTO winch hence the 2 driveshafts going forward. The driver's side shaft is for the winch.

Re: 2wd to 4wd.....just curious
 

nice, thanks! Decisions, decisions, decisions....

Re: 2wd to 4wd.....just curious
 

How deep are your pockets?
Custom modular chassis for 67-72 4x4 trucks...K5 Blazer, K10/K20 SWB or LWB ... 4 linked or IFS... SBC BBC LSX 6BT
check them out at
www.patriotchassis.com

First build was an IFS 3/4 ton LSx powere Blazer with a 4 link in the rear that's AWD like a late model Yukon Denali

Re: 2wd to 4wd.....just curious
 

You Sir are going to cost me a lot of money. Haven't seen these.

Re: 2wd to 4wd.....just curious
 

DANGER! DANGER! Thanks for the link! In all seriousness, this is an option I'd like to explore...looks like their prices are SIGNIFICANTLY more reasonable than the Roadster Shop chassis I posted in another thread a few weeks back.

Re: 2wd to 4wd.....just curious
 

I’m converting a pristine rust free 2WD 1968 to 4x4 using a 1972 4x4 frame - keeping the title from the 72 in case there issues down the road. It’s about a 2 day job to remove entire body. I’m also adding a 12 valve Cummins and Dana 60 front Dana 70 rear to the build. Hoping to be complete this summer....

Re: 2wd to 4wd.....just curious
 

So going back to the topic of transfer case......

My Gearstar stg 2 4L65E is plenty strong for my purposes.... would it make more sense to change the output shaft in order to accommodate a married np205, or leave it as she sits and include a second crossmemeber to mount a divorced t-case?

Re: 2wd to 4wd.....just curious
 

I will reiterate my vote for a divorced transfer case for simplicity of install without having to replace existing drivetrain components (transmission.)

info on the NP205 …
https://www.offroaddesign.com/tech/o...al-information

front axle install/swap...
https://diy4x.com/product.php?productid=17716

Re: 2wd to 4wd.....just curious
 

Thanks for the link, good info!

Re: 2wd to 4wd.....just curious
 

Going further down the rabbit hole...

If you use the DIY4x kit to fit the 52" leaf spring in the front, how do you determine what rate coil to use in the rear in order to provide a decent ride quality? Obviously you can get different spring heights to adjust the rear ride height to match the front, but I would also want to ensure good ride quality and handling (for a truck).

Re: 2wd to 4wd.....just curious
 

To answer your last question. The spring you have now will ride the same, just sits higher from repositioning the axle