Help ID spindle!!

[71c10RDU]

Ok I’ve done a fair amount of research and I’m stumped. I bought my 71 c10 and it already had drop spindles on it. There are no part numbers or branding stamped on them. I’m about to order tubular upper and lower arms and I’m not sure which year these are. The outter tie rods suggest they are in fact for a 71-72. However the castle nuts for the upper ball joints thread up so far the cotter pin doesn’t engage the nut. 🤷🏻*♂️ I don’t want to order the wrong arms. All my research suggests if the tie rods fit then that’s the year of the spindle, but the ball joints suggest otherwise. Maybe they installed wrong ball joints or castle nuts?? Here’s a couple of pics of the ball joints.

[67C10Step]

Something does look funny with those castle nuts run way above the cotter pins.

Hopefully someone that recognizes the spindles will be along to advise better.

[71c10RDU]

Originally Posted by 67C10Step

Something does look funny with those castle nuts run way above the cotter pins.

Hopefully someone that recognizes the spindles will be along to advise better.

From the reading I’ve done it could be 1 of 3 things. Either the castle nuts are just wrong. (Not likely). Somebody put the wrong year ball joints in, or the spindles are for a 67-70 instead of a 71-72 (but the outter tie rod ends fit and according to the site and the measurements they are 71 tie rod ends). So I’m stumped. ����

[SCOTI]

I don't think we'll be able to accurately ID the spindle just by appearances on our monitors. You'll likely have to partially disassemble things to take some measurements & do some investigating.

With further info, we can help w/informed info vs. guessing.

Beyond that? Order your control arms as planned along w/a new set of spindles so you know EXACTLY what you have.

[lolife99]

Are the upper ball joints riveted in?
This would mean they are original.

[lolife99]

Hope this chart helps,…

[Warrens69GMC]

What dual piston calipers are those? That might lead you to your answer.

[71c10RDU]

Update: I ordered an upper ball joint for a 71 and a 69. The 71 fit perfect. 69 did not. So while I have no idea why these castle nuts are so ill fitting, I do know the spindles are 71-72. I ordered my control arms accordingly. The dual piston calipers on there are wilwoods I recently installed. They work on any 67-72 disc brake spindle.

[SCOTI]

Originally Posted by 71c10RDU

Update: I ordered an upper ball joint for a 71 and a 69. The 71 fit perfect. 69 did not. So while I have no idea why these castle nuts are so ill fitting, I do know the spindles are 71-72. I ordered my control arms accordingly. The dual piston calipers on there are wilwoods I recently installed. They work on any 67-72 disc brake spindle.

Good news there & that's how I would have validated stuff.

Maybe do the same test run on some lowers if possible? That would help rule out something funky going on @ that end. Since they're not 'installed' they should be easily returned.

[Joyridin]

Are you sure somebody didn't modify those spindles? It looks like the castle nut doesn't fit because they milled a huge step in the spindle.

[71c10RDU]

Originally Posted by Joyridin

Are you sure somebody didn't modify those spindles? It looks like the castle nut doesn't fit because they milled a huge step in the spindle.

Yes I’m sure. I installed my cpp control arms last night. Everything fit great.