Modern spec spindles
 

1971 C10 Stepside
I understand that drop spindles are manufactured with the caster and camber changed to modern specs, instead of farm truck specs. I want to change my spindles, using stock height, for the updated specs. Do all aftermarket spindles have the updated specs? If not, which do?

Re: Modern spec spindles
 

I don't recall that drop spindles were configured to change geometry on the trucks. I Googled and found 7 different drop spindles for sale and none said they changed geometry. Some of those may have been duplicate manufacture I suppose.

Aftermarket control arms can and do change geometry but I could not find any spindles that did but.

Maybe the CPP modular spindles that allow for multiple brake options?

Re: Modern spec spindles
 

Yes I think you will need to change the a-arms to get some updated suspension geometry. Most new spindles are for drop or to swap to disk brake from drum on the front. I have the modular spindles and they don't make any changes in alignment specs.
The main change looked for is a caster change. There are some mods that can help that out without any changes in parts.
Dave

Re: Modern spec spindles
 

I can see how someone might think geometry is being changed, POL says this about the Western Chassis spindle included in their disc kit “Late model 1973-87 ball joints and tie rod ends are utilized improving front end geometry”. I’m sure others may have something similar in their description. Ball joints, I believe the difference is in the size and taper of the hole in the spindle, no geometry change and 73-87 ball joints fit earlier a-arms. Tie rods, the length of the adjustment sleeve was changed so the length of the threaded portion of the inner and outer tie rods also changed. The center (drag?) link length also changed but all this doesn’t effect geometry, maybe it changes steering feel slightly but I haven’t seen any mention of it.

As has been said aftermarket a-arms are available that do change geometry, just remember 73-87 parts don’t equal geometry change. RideTech, QA1, Porterbuilt are examples of arms that do improve geometry. There’s also a “caster mod” that can be done to the lower a-arm shaft and it’s mounting position that’s relatively simple for big gains in caster with stock geometry arms. Beyond that, if you want to improve handling and feel look into a quick ratio steering box, front sway bar if you don’t already have one and maybe splurge on some nice shocks.