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Old 10-07-2020, 07:50 PM   #1
EricU
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How to mod C30 A-Arms for Bags?

Well, as usual my project C30 has spiraled out of control.

What started out as a simple static drop install on my 83 big brown turd has turned into yet another fully bagged suspension on my now new to me 89 C30 (yes I now have a 83 and an 89 one-ton duallys)

The rear will be pretty straight forward as I ordered up a complete 4-link setup from PB Fab.

For now at the front I am going to use Dominator 2600 bags and mod the A-arms that will attach the Bell Tech Drop Spindles

* What are you guys (Scotti, Scotti!) using to install the bags?
I was thinking of calling BC Fab as they are kinda local and getting a bolt in top bag mount.
For the bottom A-arm (pics below), weld in a flat plate across the bottom of the lower A-arm and weld in a cup?
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Old 10-07-2020, 07:52 PM   #2
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Re: How to mod C30 A-Arms for Bags?

My upper A-arms
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Old 10-07-2020, 08:04 PM   #3
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Re: How to mod C30 A-Arms for Bags?

Not really relevant to my question, but I sure do like looking at shiny things - So here are the new shoes for the C30

And yes, I make my kids hold up my stuff and look stupid for photos!
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Old 10-08-2020, 09:55 AM   #4
SCOTI
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Re: How to mod C30 A-Arms for Bags?

The duallys call for a heavier bag than a 2600. When I built a set of arms for my dually (from some extras), I pocketed the arms for larger RE-8/Firestone F7325's/26c bags (3"min; 5-6"ride; 9"max).

Despite my efforts to allow for max room, the larger OD bags were too close to the pocket edges for me. You could possibly get away w/the smaller diameter bags on a lighter set-up (sbc vs BBC) but my BBC/TH400 requires ~100psi to achieve ride height & rides very decent. Smaller bags would likely require more PSI which adds spring rate to the mix.

Using the cups adds to the overall spring height which I didn't want. By pocketing the arms, they sat into the arms like the coils would. The way I did mine also kept the 'pocket' flush w/the bottom edges of the arm.

In the end, I wound up using PB's 1" Forward lower arms so I could use the larger bags w/o issue & used home fabbed upper plates that attach under the x-member.

I have modified/stock upper arms. Since I raised my x-member, I needed steering shaft clearance (when air'd out). All the aftermarket arms would have required multiple steering u-joints because the front bushing barrel would interfere w/the shaft on the driver side. The OE arm only required a small clearance notch & allowed using stock straight steering shaft (now the Cherokee XJ set-up).
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Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

Cubic inches is like Indiana Jones with a cheap pistol.

Last edited by SCOTI; 10-08-2020 at 10:04 AM.
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Old 10-08-2020, 02:15 PM   #5
EricU
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Re: How to mod C30 A-Arms for Bags?

Quote:
Originally Posted by SCOTI View Post
The duallys call for a heavier bag than a 2600. When I built a set of arms for my dually (from some extras), I pocketed the arms for larger RE-8/Firestone F7325's/26c bags (3"min; 5-6"ride; 9"max).

Despite my efforts to allow for max room, the larger OD bags were too close to the pocket edges for me. You could possibly get away w/the smaller diameter bags on a lighter set-up (sbc vs BBC) but my BBC/TH400 requires ~100psi to achieve ride height & rides very decent. Smaller bags would likely require more PSI which adds spring rate to the mix.

Using the cups adds to the overall spring height which I didn't want. By pocketing the arms, they sat into the arms like the coils would. The way I did mine also kept the 'pocket' flush w/the bottom edges of the arm.

In the end, I wound up using PB's 1" Forward lower arms so I could use the larger bags w/o issue & used home fabbed upper plates that attach under the x-member...
I plan on using the 2600s because that is what the PB rear kit uses and what they use for their front kit.

What you did to your lower A-arms is what I was trying to describe.

* What thickness plate did you use? 1/4" is what I was going to use.

I think that is what I am going to do first.

I'd like to eventually go to a full PB Fab front cross member - Just need to pay for my kid's school first ($$$)
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Last edited by EricU; 10-08-2020 at 02:17 PM. Reason: Old, Fat, Bald
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Old 10-08-2020, 02:39 PM   #6
SCOTI
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Re: How to mod C30 A-Arms for Bags?

Quote:
Originally Posted by EricU View Post
I plan on using the 2600s because that is what the PB rear kit uses and what they use for their front kit.

What you did to your lower A-arms is what I was trying to describe.

* What thickness plate did you use? 1/4" is what I was going to use.

I think that is what I am going to do first.

I'd like to eventually go to a full PB Fab front cross member - Just need to pay for my kid's school first ($$$)
I used 3/16 material. A larger round tube/pipe would be better (corners = possible stress points) but my local place didn't have anything large enough.
__________________
67SWB-B.B.RetroRod
64SWB-Recycle
89CCDually-Driver/Tow Truck
99CCSWB Driver
All Fleetsides
@rattlecankustoms in IG

Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

Cubic inches is like Indiana Jones with a cheap pistol.
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