Project Large Marge - Going Full Tilt

[Just-in-credible]

Well, I got the itch to build a new project…again.
After building my Tahoe chassis swapped 1960 Apache last winter, I thought I was going to be done for a while. But we all know how that goes. The winter got cold. I got to daydreaming. And here we are.

So…what did I drag home? Her name is Large Marge. I think it is a 1975 Chevy tilt cab. And I have to say, I am in love with the thing. It has a 427 tall deck BBC, with a 5 speed manual transmission.

I put a lot of time into 3D modeling how I want to build it and what I want to do, and I 3d printed little 24 scale models of how I want it to sit, and how long I want the frame etc. I have a pretty good vision of what the final product is going to look like.

The overall idea is to use junk yard parts wherever I can. I want to shorten the frame to about a 100” wheelbase, and stuff modern medium duty axles under it. This way, I have modern disc brakes, modern tire options, decent gearing etc. I will probably go with a dana S110 rear axle, and a D700F front axle. I want to run modern 10 bolt hub centric wheels, and run 22.5 or 24.5 Alcoa style wheels.
For suspension, I think I should be able to bolt on an international IROS rear air suspension, or a Kenworth air glide, or something similar. From my limited knowledge, it seems like this stuff should all bolt together. The heavy and medium duty world seems to have a few relatively standard dimensions, like 34” wide straight frame rails, and everything sems to bolt together. The shock mount, the air bag mount, the arm, and everything seems to bolt on. I am thinking with the relatively large bags from a big rig, I should be able to toodle down the road with fairly low pressure in the bags and have a decent ride.
The front might be a different story, but I am pretty sure I can make the same concept as I am using on the rear work for the front. Use an OEM style arm and bag mount, and bolt it all to the axle. It might be a bit more complicated than that, but I think it should all work.

I probably won’t run it super low, but with the air system in, I want it to be able to sit it down on the bump stops when I am parked and be fairly low. I measured it all out, and I have a ridiculous amount of room between the top of the tire and the inside of the wheel well. I think I have about 15” of room that I can lower the thing. I am thinking that the clearance between the tire and inside of the fender will not be the issue, it should be frame to axle clearance, which, I have somewhere around 12-15” as it sits right now. Keep in mind, this is with a 42” tire. I will probably run something much smaller like 32-36” range.

For the engine, I will probably just keep this engine in it for a little bit while I focus on the rest of the drivetrain, and eventually swap in either a modern big block or a diesel of some sort. I would love to put in something fun like a DT466 or an 8.3 Cummins, since I have all the room in the world and will not have to worry about length of the motor.

So this is the plan in which I am going to tackle the thing
1) Chop off the dump box
2) Chop off the tag axle and clean up the rest of the items on the frame which are not required such as the PTO and hydraulic assembly. At this point, it will be short enough and low enough to fit in my shop. I only have an 8’ door, and I think she sits right at about 8’ right now, so I will have to do some trickery to get it inside. Plus, I like doing the dirty work while it is outside, so I have less cleanup to do when I have it inside.
3) Put in a modern style clutch master and slave.
4) Fabricate a hydroboost brake master
At this point, I will probably try to see if I can get the engine running. I know myself well enough to know that I will 100% try to drive the damn thing around the yard once I get it running. And I feel like I should try to get the clutch and brakes working BEFORE I do that.
5) Install the new rear axle with air bags
6) Install the new front axle and suspension
7) Install round style aluminum fuel tanks
8) Install Exhaust stacks
9) Drive it for the summer.
So that’s the plan! I will try to keep this up to date as I build.

The cab of this thing is a bit rough, so if any of you out there know where a really clean cab is located, I would be super interested in it. The cab is the same from 1960-1980. So if you guys could keep an eye out for me, I would greatly appreciate it. Also, I am new to the whole medium and heavy duty world, so if anything I am planning does not make sense, please let me know.