71-72 vs. 73-up spindles

[MikeB]

My 69 C10 has 85 C1500 std duty spindles that use the 1.0 thick rotors. I installed them nearly 30 years ago when there weren't very many choices for disc brake conversions.

I didn't do "before and after" measurements, but even with new stock front springs, it's always seemed like the truck sits 1" or more lower than with the stock 69 spindles. In fact, even with 3" drop springs in the rear, the truck still has a little forward rake.

Does anyone here know if the location of the actual spindle (the machined shaft) on the 85 spindle is higher than on a 71-72 spindle? Or do you know if the overall spindle height (ball joint to ball joint) is different?

[Palf70Step]

When I did my first 70 with 86 C10 spindles, it seemed to sit the same. I used same 70 springs. From what I remember, the spindle seemed to be in the same place. Its been 10 years though.

[MikeB]

Thanks, Bill. I should have mentioned that I installed new springs along with the spindles. Maybe they had a lower rate than the originals, or maybe they were a little shorter.

On another note, do you remember what you used for front brake hard lines? I made my own that run from proportioning valve to crossmember. But now I'd like to get some from Inline Tube. I'm wondering if stock 71-72 lines would work, or if the tabs welded to the crossmember are in a different place on my 69. I'm not concerned about the hoses.

[Palf70Step]

Tabs are in different place. I had the parts truck so I used proportioning valve and front lines off the 86. I thing the tabs went from the back to the front of the a-arm, but I do not remember. I matched the soft lines to the spindles/calipers for easy of remembering the year part if I ever needed to replace them.