'72 C20 Suburban to 4wd
 

Hey guys, Im posting this question over here, hoping to get some additional input beyond the few of us that frequent the Suburban section.

I've got a '72 C20 Suburban with an LS swap....pretty clean truck with some minimal rust in the rockers that Ill fix at a later date. I'm looking to convert the truck to 4wd and I'm interested on what the best way to go about doing the conversion is.

This truck is used primarily as my daily driver, and weekend camper. It is also going to see duty as a tow rig once I find a used pontoon boat. I dont do any severe off roading or technical stuff, just trails, mud, sand and possibly the most important, the steep and slippery boat ramp at the end of my street.

Like I said, I'm open to all suggestions...Ill reuse the Dana 60 thats already in the rear...the only other thing I'm set on is using the Tremec TR-4050 manual trans.

I appreciate the input!!

Re: '72 C20 Suburban to 4wd
 

You have rear leaf springs already? You can use your frame but I would still find a 4wd donor vehicle. It could be anything from a Blazer to a one ton solid axle truck, as far as getting all the spring mounts and crossmembers. It's nice to get the full drivetrain and all the nick-nacks in one package. I don't know about oil pan clearance. Depends on what pan you have now

Re: '72 C20 Suburban to 4wd
 

Got it, thanks! I assume nobody sells the spring mounts and cross members? I looked around but didn't find anything.

There was a full K20 rolling chasis posted here a few years back and I passed on it....definitely regretting that now.

My truck actually has trailing arms and coils in the rear.

Re: '72 C20 Suburban to 4wd
 

So here's the next question, if I can find a basket case, long bed K20 with a good frame, is it more work to swap the 4wd components to my C20 frame, or modify the K20 truck frame to accept the Suburban body?

Re: '72 C20 Suburban to 4wd
 

I don't know if I'd swap the K components to your frame because the trailing arm coil suspension frame is different than a leaf spring frame. There are bumps directly in the middle of the wheel well area that might interfere with the springs. It might be faster to swap in a K20 frame and put the burb pieces on it. You said you want to keep your existing trans as well? So that means you want a divorced transfer case?

Re: '72 C20 Suburban to 4wd
 

Yea, that's kinda the conclusion I've come to...I think the smart answer will be to find a K10/20 Suburban with a good chassis but a body that's beyond reasonable repair and do a full chassis swap.

I plan on keeping my 6.0L LS. Right now I'm running a built 4L65E but plan on going to a Tremec TR-4050 5 speed with either a married Atlas or NP205 transfer case.

Re: '72 C20 Suburban to 4wd
 

I'm following you all around the board just to see what you do haha!

This is just me, but Ill never own another truck/burb that the chassis and cab vins dont match. I lost one sale do to someone being cautious of the non matching numbers even though I owned title to both.

Course if you are going to keep forever its not a thing =)

Re: '72 C20 Suburban to 4wd
 

Guess I am a bit different. Not sure why you are abandoning your original route so quickly. Having salvage 52" rear springs reworked is not costly. Even custom coils for the rear are not really that expensive in the whole scheme. What will the donor cost? I can guarantee you will be disappointed in the the ride going from what you have now to a stock 67-72 4x4 suspension.

Re: '72 C20 Suburban to 4wd
 

I hear ya, but this truck isn't going anywhere....too much time, money, and effort...and honestly, there's nothing Id rather have. Even if money was no object, Id send this off to Icon on the Roadster Shop for a massive $$$ restoration as opposed to buying anything else.

Re: '72 C20 Suburban to 4wd
 

Haven't fully committed to or abandoned one side or the other. The upside to a donor K20 (if I can find a decent one) is having all of the brackets, crossmember, etc. From what I can find, most of that isn't available to buy.

Additionally, if I can find a decent body shell, theres sheet metal that I'm going to need once I dig into my rusted out and bondo'd over rear quarters.

Still lots of research to do....and the availability of a usable and affordable K20 chassis will ultimately dictate whether that's even an option.

Re: '72 C20 Suburban to 4wd
 

If you have the capability to do fab work, yuo could do what you were saying in the other thread and keep your frame. You might have to modify the trailing arms or make tubular ones. These rear axles aren't centered in the wheel well any way and if you lift the truck, it just gets worse. Plus you would need to cut the perches and rotate the rear end housing to get the desired pinion angle. I'm sure you can get custom made coil springs for it or go coil over. Then just convert your front to 4x4 which can be done many different ways. A D60 would be the best option but for what you will be doing a D44 would be fine. This may be more economical and definitely cheaper and get you where you want to be faster.

Re: '72 C20 Suburban to 4wd
 

Unfortunately my welding skills are non-existent at this point, but theres a couple other forum members local in Austin that may be able to help with that.

Re: '72 C20 Suburban to 4wd
 

Mt friend did a lot of research, including finding drawings with frame dimensions/contours, before swapping a '67 Panel body onto a '72 K/10 Suburban chassis. He found that the truck frame is the same except for body mount locations. The only difference between 4wd and 2wd frames is the 4wds have about an inch more rise where it bows over the front axle in the engine area. A full frame swap using a 127" K/10 or K/20 chassis is very doable

Re: '72 C20 Suburban to 4wd
 

good info, thanks!

Re: '72 C20 Suburban to 4wd
 

This only applies to leaf spring rear suspension frames. The coil spring frames are shaped a little different in the rear. This only matters when you try to put leaf springs on a coil spring frame. Also, the rear of the frame horns are shaped differently on suburban frames than a pick up.

Re: '72 C20 Suburban to 4wd
 

Yeah. I meant comparing leaf spring suspensions. If a 2wd leaf spring C-series frame came along you could convert that to 4wd and add the suburban body mounts