Starting my 2x4 to 4x4 conversion.

[zip76]

Hey everyone, I looking to get some input on my current project.
I've got a 1979 GMC 2500 4x4 and a 1974 Chevrolet Stake truck. The good and the bad is....the stake truck has got an EXCELLENT frame that I want to utilize but of course....it's a 2 wheel drive. Now I've acquired a 1979 GMC that has quite a bit of rust on the frame and prolly some weak spots. (It's been sitting outside for 10 years) My plan is to swap out he front axle assembly and all the brackets to the stake truck. The whole reason I'm even attempting this is...is because the stake trucks frame measures 8" tall throughout the whole mid section of the truck and the GMCs frame is only 6.5" tall. I've tried to google this frame and can't find anything on it. It's one hell of a beefy frame.
I've read this thread...

http://67-72chevytrucks.com/vboard/s...d.php?t=168231

and come to the conclusion I'm going to attempt it.
Note: The 1979 Gmc has a fresh 350 and everything works great! (4x4)
The stake truck has no motor currently in it.
Everything looks as if it should swap right over with some drilling of some new holes and some new bolts and nuts. I really don't see where I'd have to do any welding?
Any tips or advice would be greatly appreciated. Thanks

[nekkidhillbilly]

keep post pics im probably gonna have to do the same since i cant find a cc from the 70s thats 4wd

[zip76]

You got it. I'll be starting this week (weather providing) and I'll have some pics up soon.

[nekkidhillbilly]

i still gotta sell my 04 im prob gonna wait to after winter just cause i cant clean it up and all

[str8axle55]

The 1 ton frames are taller. The white truck is a 1 ton, C30, and the other truck is a 3/4 ton K20. The front susp is diff on the 1 ton trucks if you want to make a true 1 ton 4X4.

[zip76]

Yeah...I'm hoping the weather holds out here...but worst case I'll have to pull one in the garage...as long as the ol lady has spot to park and doesn't get ticked...lol. Also I've got some extra leafs I'm gonna be adding to the front to make it a legitimate 1 Ton...(big ol stack)

[zip76]

Well here we go. I started the dis-assembly today. It went pretty easy. Got the whole front clip off the 2 wheel drive truck and also the front suspension assembly. A little more work and we'll be ready to di-assemble the 4x4 truck.

[Axleman]

For what it's worth... I have done this conversion before. If it is anything like mine the 4x4 motor mounts/crossmember will not fit due to different frame C section height. The easiest way to do the swap is to take the front spring hanger brackets off of the donor truck all in 1pc, ie there are 3 separate brackets (core support mount, spring hanger, and an "L" support bracket) that are riveted to the frame that create the front spring hanger bracket assembly. It is important that you only take the rivets off that hold these 3 brackets to the frame and leave the rivets that hold them together to each other intact. Knock off the core support body mount bracket on the 2WD truck. Put the 3pc bracket assembly that was removed from the 4WD truck up to the frame. Only 2 of the 4 rivet holes should line up. Put some bolts in the 2 holes that line up and redrill the other 2 so that they lineup as well (note-you may have to weld up the 2 that don't line up and grind it flat before redrilling). Once these are bolted up you can put some clamps on the remainder of the bracket and drill the holes into the 2WD frame using the holes in the brackets where the rivets used to be on the 4WD frame. For the rear shackle mount, I basically cut a section out of the vertical side of the donor frame that included the shackle hole, the 4 bolt holes for the shackle mount bracket, and the forward 2 rivet holes in the front cab body mount bracket. This will become the template to make the holes for the shackle mount in the 2WD frame. Once I had the template section cut out of the 4WD frame I knocked out the front 2 rivets out of the front cab body mount bracket on the 2WD truck and then you can bolt the template from the 4WD frame to the 2WD frame using the 2 now empty rivet holes in the body mount bracket. This will ensure that the shackle bracket is in the correct location. Once the template is bolted to the frame you can use it to drill the 4 holes for the shackle mount. Put some bolts in these and you can actually use the clearance hole as a guide for a hole saw. I don't remember the exact size but I think it was around a 1 7/8" or 2" holesaw and it pilots perfect in the template. Once you have these brackets complete the rest is easy. Take the 2WD suspension crossmember and cut it flush with the outside frame rails (basically cutoff the areas that have the mounts for the A-arms and spring pockets) and reinstall into the 2WD frame. You may need to trim the height of the 2WD crossmember if you are not planning to lift the truck any. The one nice thing about using the 2WD crossmember is that it bolts in from the bottom of the truck so if you ever need to change the oil pump or pan gasket or bearings it is as easy as unbolting the crossmember and taking the pan off. I wish I would have taken some pics when I did mine.

[zip76]

Sweet...Thanks a lot Axleman. This info will definitely help, seeing how this is a trial and error process for me. I'll be tackling the rest this week and into the weekend...More pics to come...

[zip76]

Well, Finally Made some progress. Got everything off the 4x4 truck. I used a grinding wheel to remove all the rivets...actually wasn't too bad. Everything came off fairly easy. The real bugger was drilling all the holes in the 2x4 frame...(my forearms are still a little sore) I then mocked up everything to make sure it fit before I started Painting. I tell ya what...POR 15 is the way to go. It lays sooo nice and seems to level itself out and looks like it just rolled off the factory floor. I guess time will be the real test though. Michigan Winters can be rough on a truck. Anyways...Tomorrow I'll be finishing it up and re-assembling everything. All in all this project wasn't as hard as some people make it sound. I've read a lot of forums where people look down on this kind of project but I definitely have to say it was fairly easy...just time consuming.
More to come !!!

[Red4x4]

Subscribed, This is awesome. Anything new done?

[zip76]

Sweeeet, well I getting to the final stages...(.it's all downhill from here.)
I've Almost got everything hooked back up. The only major thing I've encountered is the fact that the driveshaft is 5" too short in the rear. Otherwise everything goin great. I've actually found a nice front clip I'm thinking of buying from the local junkyard.

[yousesteers]

Are you leaving the stake bed or goingto a fleetside I think the cab and Chassis frame will have a longer wheel base thus probably why you driveshaft is also short

[Mattman2010]

Before you go about buying that front clip you should know that the 81-87(91) front clips are different than the 73-79 front clip. You can get it to work, but the hood hinges are mounted to the cab and so it takes some cutting and modifying to get that front clip to fit any of the trucks that you have.

[zip76]

Yeah I'm keeping the truck as it is. (flatbed) It's a nice steel bed and definitely HEAVY DUTY!
Yeah I figured I'd have to do a little Modding for the that front clip to fit... but I love that year front clip. (Bad Azz.)

[Red4x4]

Great work so far. More!

[str8axle55]

Looks good, nice work, made it look easy.

[jitteryguy]

Originally Posted by zip76

Yeah I'm keeping the truck as it is. (flatbed) It's a nice steel bed and definitely HEAVY DUTY!
Yeah I figured I'd have to do a little Modding for the that front clip to fit... but I love that year front clip. (Bad Azz.)

it's easyer to put the late style clip on early modle truck than it is to do an early clip on late modle truck, the late hood hinge's bolt to the fender.
the clip change will be a breeze compair'd to axle swap.
be sure to get the wire'n harrness, it have to be splice'd into your original harness.

[zip76]

Well better late than never but here's the (Almost) finished product. I've been pushing snow, driving it everywhere. So far No problems with the conversion!

[zip76]

Before and after.

[zip76]

Getting ready to start my next 4x4 project. P30 Step van body swap to a new Chevy/Gmc 4x4 Drive line. This ones gonna be fun...prolly not.lol