how much lift?

[EVL GMC]

i have been thinking of putting a lift in my truck for awhile now and i cant decide what to do.i was thinking either a 4inch lift with 2inch body,or should i just do a 6inch suspension?i would like to run 35 or 36 inch tires.in case your wondering i have a 69 gmc k20.also does anyone know if these trucks came with 4.56 gears that is what i was told was in it and the tags on the axles are gone.any info would help.

[stenbrin]

go with the 6! body lifts suck, and i would go with 36s or maybe even 37s

[CPNEJR]

the gears depended on what engine you got. a 350 got you 4:10's and i believe that anything smaller would get you 4:56 and i think you could get other ratio's but i don't exactly remember. i know that my 70 has 4:56's since it had a 307

[Yukon Jack]

If your doing springs I'd go with 6" springs rather than 4" and 2" body lift. It's a fair amount of extra work to put in the body lift.

With a 6" lift you will most likely have to address your front driveshaft. When I did a 4" lift on my 69 K20 I had to add a Double Cardon Joint to the front driveshaft.

You will also need to address your steering. Your 69 should have the Dana 44 closed knuckle axle. If you keep that axle, you will need an adjustable drop drag link to correct your steering.

You of course will have to modify your front brake lines for that much lift also.

Your rear driveshaft will probably be okay, but keep an eye on that when you lift it to make sure the length is okay.

My 69 had the 307 and 4.56 gears. Is your rear axle the Eaton HO52 - if so, it might have a No-Spin which is a Detroit Locker - your SPID on your glove box door should list it.

4.56 gears will be pretty good for the 36-37" tires.

A word of caution, assuming your truck still has the Rockwell T221 transfer case - make a habit of checking it's fluid level - I let mine get low and killed some bearings. Low oil is the lead cause of that transfer case's death.

[beechcreek]

I just ordered a 6" Tuff Country easy ride with the 8000 nitro shocks that should be here this week. This is for a 72' shortbed, stepside will i have to make the front drive shaft longer also?

[Crumley]

I just installed a 6" all spring lift in a 72 GMC long bed. So far these are the items I had to add because the 6lift. Raised steering arm and shocks came in kit. Fortunantly my front drive shaft was long enough (fingures crossed) it already has the double cardon joint. The rear drive shaft will bolt up but there is only approx 1/4" of slip play on the drive shaft, I will need to replace the rear drive shaft, it will need to be longer. Front and rear brake lines need to be lengthened, the front and rear diff vent hoses need to be lengthened. The emergency brake cables, from the frame bracket to backing plates on rear wheels came up short after lifting. I relocated the emergency brake cable brackets to the bottom of the frame. The other option is the get longer e-brake cables. The lift kit I got came with a 1" transfer case drop. This 1" drop caused the transfer case to hit the crossmember and put the front drive shaft at an extreme drive angle. So I fabricated some 1/2" spacers and raised the transfer case up 1/2" splitting the differance of the original 1" drop. By doing this the transfer doesn't hit the crossmember and the front drive shaft angle isn't so steep. I haven't driven the truck yet due to I am still restoring it so I don't know how the 1/2" spacers are going to work. I hope taht made since. I think that covers what I had to do when lifting a 1/2 ton to long bed.

[NEVERENOUGH]

Crumely post up some pics of that bad boy. I am getting ready to do the same to my 69 gmx 3/4 ton. I am torn between a 4 inch and a 6 inch. I know that I am going to do a shackle reversal in the rear and if I go 6 I will run 2 inch springs.

[Crumley]

10-4, Neverenough, I have started a build thread in the project build section listed as 72 GMC 4x4 rebuild (Crumley). I have posted a few pictures of the tear down and the slow process of rebuilding. I have a ton (a picture is worth a thousand words) of additional digital disassembly pictures in my computer files (not enough space here to even think about printing). If you would like to see aditional pictures of the restore I will down load them. I try and up date the build thread as I can.

[Crumley]

With all that said, Yukon Jack stated he had to install a longer front drive shaft with a doudle cardon joint. Which has got me to thinking have I installed something wrong.

My front drive shaft fit (with a 1/2" drop on the transfer case) when the truck was lifted 6" but the rear will bolt up but there isn't enough slip to run on the truck.

I have a question, with the 6" lift kits ya'll have installed did they come with a tranfser case drop?

Those of you who installed the 1" transfer case drop, did you encounter a extreme angle on the front drive shaft and an interferance problem with the back of the transfer case hitting the cross member?

Or should I leave the transfer case in the stock position and lengthen both drive shafts?

[EVL GMC]

yukon i believe my rear axle is a dana 60 i dont know much more about it,theres no tag on it to know what gears are in it,and i checked the glove box and there are no stickers.as far as the transfer case i believe its an np205 i have looked at many post and pics on this sight and as far as i can tell its the 205.and i just wanted to thank everyone for all the help,i have never seen so much help on a site like this usauly u get smart a##s and rude remarks and you dont see that here so thanks.

[EVL GMC]

allso is that shackel reverse kit real worth it or am i fine just doing a normal lift kit?