[SCOTI]

Originally Posted by bigtexasrob

Hi all, first post to the site, came to the forums because I can’t find answers to the questions I have. Guess that’s what I get for “needing” a dually. Anyways, let’s jump into it. Truck in question is a ‘74 C-30 dually longbed that originally had the 350 and a “four” speed.

1) What differences are there between the C-30 and C-10 front suspension member? How different are the control arms?

2) Do I need to shorten/modify the front suspension member to lay the truck flat on rails, or will control arms and drop spindles handle it? It seems that the front member sticks down too far to set the truck flat.

3) Any resources for or members here that fabricate custom control arms? I’m looking for something a little different.

The frame rails are taller on a C30 vs a C10. Spindles & springs will get it close but not on the rails. You'll need about another 1.5". Do a pancaked x-member or z'd front frame, spindles, + bags & it will plant the x-member/rails.

The upper control arms on a 74 C30 are like pre-73 C10's utilizing the rubber lined steel bushing. Ball joints are interchangeable. The lower arms are also like pre-73 C10's as far as the bushings but utilize a larger OD lower BJ so they're not interchangeable.

What specifically are you wanting as far as modified a-arms?