70 Flatbed Cummins Transformation

[70C10Ginger]

Hello fellow gearheads,

IÂ’ve read so many of your builds, questions, responses, and amazing problem solving stories. Admittedly, I am so jealous.

Now I have my own money pit!!!! I grew up in a tiny town in Utah next to the Grand Staircase, and used to drive by this truck on the bus as a kid.
I grew up, fell in love with the way 67-72 gym trucks looked, after being a square body guy for my teenage years. We all learn sooner or later though haha.

Wound up buying the pig for a fire wood/work truck. First day, blew apart the front drive axle.... Not telling why. After a couple months, and having to have it get impounded to be able to get any form of title without it being a nightmare, I drive it up to Salt Lake to start working on it and making it useful. Leaked all the gear oil out of the rear Dana 60 while driving and resulted in blowing that apart as well.

So, now that youÂ’re basically caught up. Today (3/28/20) I took out the destroyed Dana 60, and replaced it with a GM 14 bolt corporate AAM with disc brakes. Now that I have it resting on the new leaf spring perches, IÂ’ve got them measured out for Monday to have new U-bolts bent up for me. I think I have a simple solution for the parking brake, but have no idea what IÂ’m supposed to do about the soft brake line going from the stock hardlines on the frame, to the new 14 bolt.

Anyone done this before that could help me out?

[57taskforce]

Originally Posted by 70C10Ginger

Hello fellow gearheads,

IÂ’ve read so many of your builds, questions, responses, and amazing problem solving stories. Admittedly, I am so jealous.

Now I have my own money pit!!!! I grew up in a tiny town in Utah next to the Grand Staircase, and used to drive by this truck on the bus as a kid.
I grew up, fell in love with the way 67-72 gym trucks looked, after being a square body guy for my teenage years. We all learn sooner or later though haha.

Wound up buying the pig for a fire wood/work truck. First day, blew apart the front drive axle.... Not telling why. After a couple months, and having to have it get impounded to be able to get any form of title without it being a nightmare, I drive it up to Salt Lake to start working on it and making it useful. Leaked all the gear oil out of the rear Dana 60 while driving and resulted in blowing that apart as well.

So, now that youÂ’re basically caught up. Today (3/28/20) I took out the destroyed Dana 60, and replaced it with a GM 14 bolt corporate AAM with disc brakes. Now that I have it resting on the new leaf spring perches, IÂ’ve got them measured out for Monday to have new U-bolts bent up for me. I think I have a simple solution for the parking brake, but have no idea what IÂ’m supposed to do about the soft brake line going from the stock hardlines on the frame, to the new 14 bolt.

Anyone done this before that could help me out?

So I’ve thought a little about this. One of my AAM 14’s has the factory brake hose on it still from the 08 it came from. What I don’t remember is if it’s 1/4” line at the frame end. If it is, all you’d likely have to do is buy a rear brake hose from a truck with an AAM in it and use that. You may also need to change the fitting on the frame line to metric, that’s as easy as cutting the flare off the old line replacing the fitting and re-flaring the line. I’d assume that the frame is 1/4” line, but don’t know for sure. I could tell you Monday when I get back to the shop my stuff is in. I’m quite certain that it is 3/16 from the soft line Tee to the rear calipers. If you’ve got those lines still on the axles the fittings are likely metric thread in which case you’ll definitely need the rear hose from an AAM 14 bolt equipped truck. Hope this makes atleast a little sense. Can’t wait to see the progress on your truck!

[70C10Ginger]

Originally Posted by 57taskforce

So I’ve thought a little about this. One of my AAM 14’s has the factory brake hose on it still from the 08 it came from. What I don’t remember is if it’s 1/4” line at the frame end. If it is, all you’d likely have to do is buy a brake hose from a truck with a AAM in it and use that. I’d assume that it is 1/4 but don’t know for sure. I could tell you Monday when I get back to the shop my stuff is in. I’m quite certain that it is 3/16 from the soft line Tee to the rear calipers. If you’ve got those lines still on the axles the fittings are likely metric thread in which case you’ll definitely need the rear hose from an AAM 14 bolt equipped truck. Hope this makes atleast a little sense. Can’t wait to see the progress on your truck!

Ill take pictures of the hose that I have tomorrow. I am trying to identify the year of the 14 bolt that I have. The dude I bought it from said 08 or 09, I think..... so I want to know haha. Once I found that out, I was going to buy the stock soft line for that axle and hope that it bolted into the hardline that I had.

Ive got more pictures of the flatbed with a pretty bad body, and I’ve sourced a 70 c15 that came from the same factory as mine, just a couple months later. It has factory a/c, and only surface rust on the body, but the bed needs some love.

[70C10Ginger]

Ok, so I think I made a goof when I took the rear axle to a shop to have them weld on new leaf spring mounts. I know, I know. Should have done it myself. But I don’t have any of the equipment that I would need to even begin to do that. Apparently their mounts are about a 1/2” taller than stock gm mounts from 1970. So I’m not sure if that will effect the angle of the pinion... I had them weld it on a +2* because that’s what I found from everything that I had read and looked up. On top of that, when I had them remake the brake lines, I didn’t know that the 14 bolt I had had the junction block on the drivers side, while my k20 has stock passenger side lines. So I either need to have them rebend new lines and place the junction block on the passenger side, or find a 24” brake hose...

[70C10Ginger]

And here is my current brake problem



I’m also thinking that the stock drive axle is not going going to work. The stock u joint doesn’t fill the 14 bolt socket fully. There’s a half inch gap on both sides

[57taskforce]

If I’m understanding you correctly, As far as I can see, the extra height in the perches shouldn’t effect the pinion angle too much because all your doing is dropping the axle as an assembly down that 1/2” not rotating the pinion up or down. If you’ve got some pictures you could post that might help us see what exactly you’ve got going on. As for an extended brake hose if you need one you can get them online for lifted trucks but I think I’d rather have the axle lines set up the way the factory did. It’s not a big deal to flare new lines, the tools are cheap and if you get nicop lines they bend and flare really and won’t rust.

[70C10Ginger]

And here is my current brake problem



I’m also thinking that the stock drive axle is not going going to work. The stock u joint doesn’t fill the 14 bolt socket fully. There’s a half inch gap on both sides

[70C10Ginger]

Originally Posted by 57taskforce

If I’m understanding you correctly, As far as I can see, the extra height shouldn’t effect the pinion angle because all your doing is dropping the axle as an assembly down that 1/2” not rotating the pinion up or down. If you’ve got some pictures you could post that might help us see what exactly you’ve got going on. As for an extended brake hose if you need one you can get them online for lifted trucks but I think I’d rather have the axle lines set up the way the factory did. It’s not a big deal to flare new lines, the tools are cheap and if you get nicop lines they bend and flare really and won’t rust.

Do these help. As you can see, there’s about a 1/2 inch before the stopper pin for the receiver on the axle.

[57taskforce]

You need a 1350 series to 1410 series conversion u joint I believe.
Something like this should do it.
https://www.dennysdriveshaft.com/c42...4.188_out.html

[70C10Ginger]

So thankfully, my local driveline shop is still open during the Corona virus outbreak. And they have that conversion ujoint in stock. Finally, some luck. After getting four new leaf spring mounts and that conversion joint, I’m still a little stuck on the brake hose. I’d love to learn how to do it, but of course have some questions. Can I just rotate the proportioner valve 180* and put it on the other side of the differential and run new lines? Cause that sounds way easier that trying to find this hose right now?

[57taskforce]

What you could do is swap your axle side lines from one side to the other. And then move the brake hose to the other side of the rear end where it would hopefully reach the frame line.

[70C10Ginger]

Originally Posted by 57taskforce

What you could do is swap your axle side lines from one side to the other. And then move the brake hose to the other side of the rear end where it would hopefully reach the frame line.

Awesome! Time to go to China freight to get the tools, and then get some of that fancy brake line you told me about. Can I reuse the “new” nuts on the current brake lines. They’re literally brand new, I would just have to take them off the hose??

Ok. I got the beast home, and remembered everything that I have to do to get it to be my daily driver for the next couple of months... Anyone know of some tree work needing to be done in Utah? Have saw; will travel.

I have a single barrel carb that I’m sure came stock. I don’t want to blow the engine up before I can gut it and rebuild it. So should I just rebuild the single barrel in it for right now, or slam a four barrel on it and save my pennies and do the engine very first??? I need guidance and ideas to bounce off of!

Regardless. Taking this thing home from the yard it was at, was an absolute dream. I’m so excited to finish this build five years from now....

[70C10Ginger]

So I’ve made a good amount of progress. I replaced the old school points system with an MSD ignition coil, msd heat module, msd cap and rotor, new Ac Delco plug wires and plugs. Wow, this thing absolutely SCREAMS. Still need to pull out my timing light, and get it totally dialed in, but for now I’m calling it ok.

So onto the Aardvark. I did wind up having to switch the brake hose attachment to the passenger side of the axle. Two bolts, and some quick hose bending later, I’m ready to attach the new hose to the old hardline. Or not. The bolt is so seized and already stripped, that I’m at a loss. I’m getting a blowtorch and some vice grips to it tomorrow.

Here’s a link to the thread i started about setting up the new vacuum lines, cause I’m super lost haha
http://67-72chevytrucks.com/vboard/s...33#post8709633

[57taskforce]

Originally Posted by 70C10Ginger

So I’ve made a good amount of progress. I replaced the old school points system with an MSD ignition coil, msd heat module, msd cap and rotor, new Ac Delco plug wires and plugs. Wow, this thing absolutely SCREAMS. Still need to pull out my timing light, and get it totally dialed in, but for now I’m calling it ok.

So onto the Aardvark. I did wind up having to switch the brake hose attachment to the passenger side of the axle. Two bolts, and some quick hose bending later, I’m ready to attach the new hose to the old hardline. Or not. The bolt is so seized and already stripped, that I’m at a loss. I’m getting a blowtorch and some vice grips to it tomorrow.

Here’s a link to the thread i started about setting up the new vacuum lines, cause I’m super lost haha
http://67-72chevytrucks.com/vboard/s...33#post8709633

Very nice! Transmission fluid and heat work well to break those rusty fittings loose.