We have a Duff 3.5 system installed on the 68 we are rebuilding. It came with 6.5 degree radius arm bushings. We have it stripped down to the frame so it is riding high so I wasn't too concerned that the coils had some bow in them. But yesterday we set the engine in and there is still some bow in the springs. I was also taking a closer look at the castor and it looks to have positive castor. So I started to worry about whether we might have screwed up on the installation of the bushings. Pulled the radius caps today and we have them installed per the markings on the bushing, front bottom and back bottom.

So now I have a couple of questions. I am wondering if after we get the trans/transfercase and body back on if it will sit down enough to get negative castor? Is it possible that 6.5 degree bushing can not be enough with a 3.5 lift?

Also, I removed the caps without removing the springs. What are the chances I can get the caps back on without removing the springs and shocks?

thanks

I don't recall what lift requires what bushings, but I doubt you'll get enough negative caster from installing the rest of the drivetrain. I think you'll need to source new bushings are experiment with the ones you have. Install the front ones so that fat side is at the bottom and the rear ones so the fat side is at the top.

J.D.

Aren't the 4 degree bushings supposed to be with that lift? I have the 6.5 with my 5.5" lift. What about the rear radius arm bushings. Are they they cheap flat ones or do they have the angle molded into them to get the rear pointed in the correct spot.

As for the bow in the springs, it is pretty normal. I have a picture somewhere of my 5.5 springs and they are bowed out pretty good.

Thanks, I think what I'll do is remove the springs and reinstall the bushings and cycle the suspension and measure the castor at various ride heights and see what we have.

I think the WH kit comes with 6 or 7 degree bushings

I think most vendors have settled on this arrangement for 3.5