Lowering 79 C35 crew cab dually

[Big Chip]

I am looking at the Western Chassis 3/5 drop kit and I have a question regarding the installation and I am kind of looking for someone who has installed this particular kit or if there is a better option out there.

My main concern is having to notch out the bed supports to clear the C-notch and the rear shackles. I would rather not do that if it is at all possible. Is a 5" drop in the rear even low enough that there would be an interference issue with the bed?

I also need to replace the exhaust and I was looking at the Flowmaster crossmember back kit and so I guess my next question is: which one should I do first, exhaust or lowering?

 

[Craig 85]

Lower it first, then exhaust.

 

[smoothandlow84]

From my experience you will have to notch the rear bed frame supports if you install lowering shackles. Lowering the rear end with lowering shackles requires more "sweep" clearance for the longer shackles to move during the suspension cycling (longer shackles, more drop, more movement and the shackle will interfere with the bed rails). If you are lowering the rear with a axle flip kit, notching shouldn't be necessary. Most people like the added rear axle clearance and notch the frame regardless while they are under the truck. If you load the bed of the truck, obviously you may run into bottoming out issues. I have lowered numerous vehicles and I suggest that you lower your truck one step at a time in order to see what clearance issues if any you have. With the dually, installing a rear flip kit should give 5-6" of drop, unless you remove leaf springs to soften the ride. Removing the overload leafs will lower the rear another 1-2 inches and soften the ride more as well. I would start off with a flip kit first, check for clearance and defininately do the exhaust AFTER the rear is lowered to your liking. Be sure to install a good set of gas charged shocks, especially with the added gurth of a dually.

I had my square regular cab shortbed lowered 3-5....then 5-7....now it is fully bagged for adjustability. If I had it all to do again I would have just dove in and bagged it to start. Bagging is definately more expensive, but completely adjustable for different driving conditions.

Don't forget to get the alignment done after lowering is done. When you have the front end apart, I would also suggest replacing the ball joints, pitman arm, and any other bushings or linkages that are worn or sloppy. You're gonna have greasy hands anyway and it will effect the alignment and handling too.


Be sure to post up pics during the process.

 

[Big Chip]

Thank you for the quick responses!

I had toyed with going the airbag route and maybe I just need to wrap my head around doing it. They definitely look better lower. Is there a system I should be looking at if I go airbags?

 

[smoothandlow84]

Check out Switch Suspension online. They have complete front and rear kits...bags all the way around (2500lb units)...twin Viair compressors, 3/8" air line (dot rated), accuair 5 gallon aluminum tank with the valves mounted IN the tank....and a switch box.....complete for $2k. You could save some money by going with a steel tank, but they will rust over time even with moisture seperators. I decided to go with an aluminum tank with the valves inside for not only a rust free tank, but a cleaner setup. The rear would be a four link with a panhard bar for your truck. If you weld, or have access to a weld shop, four links are pretty easy to install with a bit of patience. The trick to four links are the measurements and tips from those that have installed them before (I would be glad to help out with tips and tricks). The front bags with mounting plates just replace the coil springs. You would of course need drop spindles in the front to get the maximum drop with the bags. You could use your oem upper and lower control arms (I did). I fabbed and did my own welding with a mig setup. The rear with the bags requires notching of the frame above the rear axle and building your own or buying a prefabbed bridge to mount the rear bags to. This is the "basic" bag setup. Of course if you do a cantilever rear setup, or something crazier, the cost increases.

As you can tell...bagging a truck requires a bit more time and planning. My complete front and rear bag install and fabrication took my four days to complete from start to finish at my house. The front took literally about 6 hours. The rear because of the welding and removal of the leaf springs and hangers obviously ate up most of the time.

If you call Switch Suspension, they are great at explaining the ins and out of everything. The are also air ride installers unlike most counter sales people. I am thrilled with how my air ride setup installed and how much better the ride is.

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This is the rear bridge that I built to mount the rear bags to and cover the notch in the frame....its 3/16" steel.

 

[smoothandlow84]

Side view...

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aired out, my headers and the front bumper valance are 1-1/4" from the pavement and the front and rear tires touch the underside of the wheel tubs (its a custom theft deterrent since it can't be rolled...lol)

 

[Big Chip]

That is one sweet truck!

It looks like I will have to make a phone call to Switch Suspension, all I could find were C10 systems online. I am really looking forward to getting into this project!

 

[smoothandlow84]

Sweet.....another bagged convert......!


Be sure to post progress pics and ask questions if you need to.

 

[smoothandlow84]

That is one sweet truck!

It looks like I will have to make a phone call to Switch Suspension, all I could find were C10 systems online. I am really looking forward to getting into this project!

Thanks! I still have some more work to do with the little details.

 

[Big Chip]

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[Big Chip]

That’s my jalopy when I got home from Oregon with it and after I got rid of some of the extraneous junk off it.

 

[Big Chip]

I flew out to southern Oregon, met the guy at the airport and proceeded to drive about 2800 miles back to Michigan. I am glad he was honest with me on reliability!

 

[74 Shortbed]

Nice dually..

 

[Big Chip]

Thank you, 74. It is going to be a "work in progress" for a while I imagine.

 

[74 Shortbed]

Thank you, 74. It is going to be a "work in progress" for a while I imagine.

Looking forward to seeing the progress.