'70 1/2 Ton GMC LWB 4x4 Newbie Build

[MyMach5]

This is my first time refurbing any kind of car. I’d like to say I'm self taught when it comes to working on cars and trucks but I really owe what I do know to great friends, family and boards like this. I hope you guys enjoy watching this build as it gets completed over the next year or so. I'm definitely still learning so advice is always welcome.



Here are some pics from my first big project...replacing the 4 wheel manual drums with power front discs and a 4" Superlift suspension upgrade.

Here a few pics of the how the truck looked when I bought it:

[MyMach5]

This is us taking the components off of the '75 Dana 44 front end. We’re planning on swapping the disc parts over to my original '70 Dana 44.

[MyMach5]

Newly painted caliper brackets installed.


Rotors on


Getting the bearings set correctly






Calipers installed


We're thinking we're getting close


The old master cylinder

[MyMach5]

New power booster, master cylinder and proportioning valve.


Houston we have a problem...the calipers are hitting instead of the steering stop bolts


We can make this work...


This should work...right?!


It didn't...time for break and some stress relief.


So you have to replace the knuckles-out on this swap which I read on this forum before I started...I forgot. We did spindles out, got everything back together and, well, you can see above what we tried. So in a little stroke of luck, we counted the teeth on the ring of the donor '75 front end and it matched my existing gear ratio. So, instead of swapping the knuckles, which didn't seem easy, we're doing what all of you guys recommended as the easiest way to do it from the beginning...swap the front ends.


The original front end coming out


The front suspension was really tired and my wife Molly is exceptionally cool so she gave me the go-ahead on a new 4" lift. After a lot of research I went with Superlift because they use teflon pads in between the springs and they tapper their springs as well. The guy at our local 4 wheel store recommended the Hydro shocks over the Nitros on leaf-spring trucks because the ride is a little softer.

[MyMach5]

Did GM put these "end caps" on the front spring mounts?




New front end is in.


Got the wheels and tires on the front to see how it looks...33" x 12.5" BFG AT's on 15x10's






I'll need longer u-bolts in the rear if I want to keep the overloads...these sit on top of the spring pack. For now, I'll just use the blocks and stock springs. Eventually, budget allowing, I'll replace the rear springs with 4" lift springs.




Everything's in...ready for wheels and tires.

[MyMach5]

All done...now I just have to bleed the brakes and chase the hydraulic leaks in the new braking system...it took the better part of a day to get it all sealed up


Backing it out to drive it home.



Up next: body work, bed replacement, interior work.

To be continued...

[Rack Man]

Nice looking truck for sure...will be a fun project.....

FYI, your pics are GINORMOUS...You probably should resize them....here is a free & easy to use "resizer program" if you need one....

http://pixresizer.en.softonic.com/

[MyMach5]

Thanks man. You're right about the pics. I'll resize them as soon as I can.

[70 beast]

as to the spring mount caps on the front driver side: i wanna say that they were factory. both my gmc's had them (po torched the one off my k25).

what they are for i have no idea.

[MyMach5]

Hey Guys. I tried to resize a few of these...a few at the top and a few at the bottom of my posts. Could you guys tell me if these look better or they need to be smaller.

[Chevy1TonFun]

THe resized pics are a good size. Keep up the good work. The truck is looking good.

[jeffspower]

Sharp truck! Lookin even better now

The "cap" was used with a "kicker" bracket installed on the frame behind the springs rear eye. I think the idea was to try to keep the front axle in position in a hard front end collision. With the fore & aft style drag link, the truck would turn on its own if the spring eyes tore out and the springs were free to slide back & forth.

I'm basically doing the same thing on the '68 right now. Swapping out the closed knuckle/ manual drum junk for a '75ish disc front end, and used power booster & lines I found. 3.73's here also- I think they are a pretty good gear with 33" tires.

[MyMach5]

I'm actually not exactly sure what my gear ratio is but when we counted the teeth on the ring my brother-in-law (who's in a couple of pics above and has really helped me out) said they look like a "freeway gear". Would that make them 3.42s?

[jeffspower]

I can't quite tell in your pics which rear end you have. Originally it could be a D44 or GM 12 bolt. It kinda looks GM? Most in the era with a GM rear had 3.07 or 3.73. Dana rear I can't recall seeing 3.07, but mostly 3.54 (not offered in the GM) and some 3.73. I don't think they used 3.42 until the early 80's in a 4x4.

Do you remember the tooth count? here's a list of the Dana 44 combos.

ratio RG/PG
2.87: 43/15
3.00: 45/15
3.07: 43/14
3.23: 42/13
3.31: 43/13
3.50: 42/12
3.54: 46/13
3.73: 41/11
3.92: 47/12
4.09: 45/11
4.27: 47/11
4.56: 39/8
4.78: 43/9
4.89: 44/9
5.13: 41/8
5.38: 43/8
5.89: 53/9

[jeffspower]

Oh, and I thought I had seen in one of your posts that you had mentioned 3.73's. My bad. I guess it was my willful thinking kick'n in since I like that ratio alot

[MyMach5]

If I remember correctly it was 43.

The rear is Corp 12 bolt so I'm guessing my ratio is 3.07. That list of ratios is pretty awesome.

Thanks for all the help.

[steelhorse]

Nice looking truck!

[Frizzle Fry]

Lookin good!

[MyMach5]

Thanks guys. Here are some pics after I cleaned it up for Beaches Cruisin' last night.

[nvrsatisfied]

build up looks great. can't wait

what is the matter with the bed, does not "look" like to much body work.

love LWB reminds me of my old setup i had similiar

[MyMach5]

It's a wood bed. The oak looks original and one of the previous owners "fixed" some it with scabbed in plywood. Needless to say there are a few holes in it. The strips and hardware that hold the bed in are pretty shot too.

Other than that the body work is just some pretty standard stuff:

Driver side cab corner
Driver side rocker panel
Lots of superficial rust spots where the paints chipped
Overall it really needs a good sanding, prep and paint

[MyMach5]

I was getting a lot of vibration out of the front of the truck in 4x4 after the lift. It turned out the slip yoke on the front drive shaft was really worn out and had a lot of play. Also, the front shaft on my pickup was a conventional two joint shaft. The guys at Tom Woods Custom Drive Shafts recommended a Double Cordon CV shaft for smoother operation with the lift (they also thought that was what originally came on the truck). So I measured and got Tom Wood's heavy duty front drive shaft.

Old Front Shaft









The new and the old





Cleaned up the differential yoke



Cleaned up the transfer case side as well



New front shaft installed



I couldn't be happier with the quality and the truck runs smooth as butter in 4x4.

[silver7]

My front spring shackle also had what looked like a strip of steel welded across the face. I always wondered if this came from the factory this way.

Love the truck.

[Yukon Jack]

Great build thread! Nice work.

[msgross]

first time i've seen this one, nice...

what do those axles cost?