: 88 K20 Burb suspension advice needed.


Mobydick
12-28-2005, 07:07 PM
I have an 88 K20 Burb. It has the following: (correct me if I get any of this wrong) 350 engine, not sure about the tranny, its a three speed, th350 perhaps?, NP208 TC, Dana44 up front ???, and a GM 14BSF in the rear. One thing I have noticed is that the axle U-bolts are already flipped, I.E. "nuts up". I know places like ORD sell U-bolt flip kits for those whos U-bolts are pointed down. Did all 20 and 30 series rigs come stock with the U-bolts turned up like mine?

I am starting my build up of this truck and want to begin with the suspension. I bought it used, at some point 33 x 12.50 on 16.5 rims were installed, other than that it is stock. The truck is being used as a hunting/camping off road people mover and support/tow vehicle. I use this truck off road in the mountains of NC and VA. It will not be a trail vehicle. However because of the use in the mountains I need to pick up some articulation without adding a lot of lift. There have been times when I have come close to three wheeling it. And I have had some occasional rubbing with the 33s. However, because of its intended use, with people and equipment in and out all the time I don't want a huge lift. My intention is to lift it 2 inches and keep some version of the 33s. (I see no need to up grade to the D60 and 14BFF for this level of use.) I would like to have as much articulation as is reasonably possible while keeping the leaf spring setup. If this means that I have to cut sheet metal, I would rather do that than go any higher.

So I need some advice on what my best options are to do this with a short lift. My basic plan was to have an ORD party under the truck.

The rear would consist of ORDs 2.5 inch shackle flip kit, new shackles and greasable bushings all around. My first questions is why does ORD make these flip kits in 2.5 height? Assuming for a second that I am going to use a 2 inch lift spring in the front, won't this have me high in the rear? Also what should I do about the rear springs? I am assuming that the shackle flip will move my axle forward, which will need to be corrected. But I dont want to use zero rates because I don't want the additional lift. Also I am assuming that softer springs will improve articulation. Is my best option to have a custom spring made in the stock size but with a softer spring rate and move the axle pin back?

My plan for the front was to use 2 inch lift springs, HD shackles and greasable bushings all around, and the ORD swaybar kit.

Any other suggestions for improving the articulation of this vehicle?

How much softer can I go with the springs and still tow with this truck?(say no more than a off road rig. 5-6000 lbs) Will I really gain that much articulation with softer springs?

What about changing shock geometry to increase articulation? The rear is the standard, one to the front, one to the rear, just outside the frame. The fronts have a bit of a twist to them. Would going to a longer shock help? I would be willing to go to shock hoops or some other design. (a V or inverted V in the rear?) Cutting the front inner fenders is fine as is rebuilding the inside wheel wells higher in the rear. I wouldn't want to cut through the bed/floor though.

Any suggestions or advice will be appreciated.

dubbyx
12-28-2005, 07:17 PM
look at some of the links on this thread:

http://www.pirate4x4.com/forum/showthread.php?t=425940


don't hold on to the 2.5" lift... go with 52's, shackle flip rear.

u2slow
12-28-2005, 07:28 PM
Did all 20 and 30 series rigs come stock with the U-bolts turned up like mine?


Some do some don't. Even my '84 C20 (2wd) Burb has them turned up.

Mobydick
12-28-2005, 07:38 PM
look at some of the links on this thread:

http://www.pirate4x4.com/forum/showthread.php?t=425940


don't hold on to the 2.5" lift... go with 52's, shackle flip rear.

I saw that thread. One thing I dont understand, are U saying I should use a rear spring from a K5 on the front? Exactly how much lift does that provide? I assume it is some since the stock K20 front springs are actually curved down. Also won't this put me in a situation where I would have a lot more articulation in the front than I could achieve in the rear? Also isn't a K5 spring too light for use on a K20?

Oh and just to be clear, the truck isn't lifted at all right now.

Fordtrucks
12-29-2005, 02:36 PM
Yes use rear 52s up front.I did on my 81 F150 truggy they were out of an 84 burb and I added 2 leifs to hold my Big Block and I love them.Also a LOT longer shackel in the front will help with your doun travel and if you do it wright you will end up with the 2 inches of lift that you want and gain travle wich helps articulation.However it will be harder to get flex when only adding 2 inches.And I dont know how much lift you would gain with a 52 front swap cause I have never done it on a chevy,However if the lift is to much you can allways loose like 4 inches by mounting the axel on the top of the leafspring instead of under.

Fordtrucks
12-29-2005, 02:39 PM
PS the shackel and shocks are the big holdup on the back aswell.Longer shackel front and shackel flip on the back aswell as longer shocks will all help.

bigyellowjimmy
12-29-2005, 09:24 PM
The rear would consist of ORDs 2.5 inch shackle flip kit, new shackles and greasable bushings all around. My first questions is why does ORD make these flip kits in 2.5 height? Assuming for a second that I am going to use a 2 inch lift spring in the front, won't this have me high in the rear?


the rears sag so the extra .5" probably wont even level it out after you get fresh springs in front.