A-Arms question - Drum vs disc

[CPNE]

I need a definative answer before I start on this disc brake conversion.

What I have:

1. 67 3/4 ton 2wd rolling chassis - stock
2. 72 3/4 ton 2wd disc spindles rotors, calipers, etc - stock
3. 72 3/4 ton 2wd center drag link - stock

What I intend to purchase:

1. 72 3/4 ton 2wd inner/outer tie rods and adjusting sleeve
2. 72 3/4 ton 2wd upper and lower ball joints

My question is:

Can I simply remove the stock drum spindles and ball joints and replace with the above? Or will I have an issue trying to get the disc ball joints into the stock drum a-arms?

I am aware that the brake lines route differently and the lower a-arm will need a bracket welded to it for the caliper hoses. Other than that is this a slam dunk?

Thanks

[Garage Freak]

I'm doing the same conversion.

Does anyone have pics of the routing of lines and bracket?

Thanks,

[Palf70Step]

Only thing I know for sure is that the part on the arms for holding your brake lines differ on the drum vs disc. I am not positive on whether you can mount the ball jouts/spindles for the disc years on to a drum arm.

[CPNE]

Originally Posted by Palf70Step

Only thing I know for sure is that the part on the arms for holding your brake lines differ on the drum vs disc. I am not positive on whether you can mount the ball jouts/spindles for the disc years on to a drum arm.

That is the crux of my question

[nightmare]

i've heard that the arms are the same, 67-72, but that the ball joints changed in 71 to accommodate the disk brake spindles. IIRC you can just change the ball joints in your 67 arms to the 71-72 style for the disk brakes and be just fine.

Originally Posted by CPNE

I am aware that the brake lines route differently and the lower a-arm will need a bracket welded to it for the caliper hoses.

it may be different for a 3/4 ton, but for a 1/2 ton, the brake lines run on the upper a-arm, not the lower. when i did mine, i didn't have to use anything else for the brake lines. they just connected to the where the old drum brake lines used to be.

[rlm316]

The upper arm is no problem, the new joint for the disc spindle just bolts right in. I think that the bottom joint should be ok as well. When I was buying all the parts for mine, alot of the parts were interchangeable from my '70 right up to the '91 donor front end. There is a major difference in the travel stops that are welded on the lower control arm. The spindle shapes are different enough that I didnt feel right not using a newer set of lower arms. Hope this helps.

[my67chevytruck]

I know on 1/2 tons the UCA and LCA are the same part # for 67-72, the difference is the ball joint and the brake line mounting location. I helped talk a member on this board go through this same thing on his 1/2 ton and he did not have any problems that i recall.I would almost bet the 3/4 ton would switch out as well... Maybe Wes or someone will chime in and verify.