Help lowering an '83 C30 Crew Dually

[SCOTI]

Originally Posted by Big Chip

I got the Belltech Spindles and Western Chassis springs from Switch Suspension. The rear notch and airbag brackets with the crossbar are their design as I understand it. It has a flange on the inside instead of just the C welded to the part that bolts to the frame.

Unfortunately, although the plate on the inside helps, its not enough to return the frame to its original strength which to me should be everyones goal (as strong or stronger than it originally came).

An engineer (structural engineer specifically) did the math for me on that type of notch (I based it off of my duallys parts). I figured since I used 1/4" material for the notch portion as well as 1/4" boxing plate I would be @ stock strength. Imagine my surprise when his calcs said it was less that 25% of what a factory rail was.

Do people have them installed w/o issue? Sure.
Have they towed w/o issue? Sure.
Have they been selling stuff like that for years? Yep.
Does that make it as safe as stock? Nope.

I want my modified truck safe so I don't risk killing someone in your family.