[Guest]

I bought a set of steering knuckles sold to me as 5/8" - but I'm not going to use them and have a buyer for them. However I don't want to sell something unless I can without a shadow of a doubt know it used the 5/8" lower ball joint. Are there any numbers on the spindle that would indicate which version it is, without requiring a 5/8" ball joint? I did a quick check and didn't come up with any GM part numbers on it.

 

[Guest]

One way to tell without any specific measurements is to see if the bottome ball-joint hole is bigger than the upper. All 5/8 spindles had the same upper hole size as the 9/16 ones, so i am saying just the bottom hole is bigger on a 5/8 spindle.

I am not sure if casting numbers would help, since I think they are the same as the 9/16 ones. The bottom hole was just machined a 1/16 bigger.

 

[Guest]

About the only (and best) way is to get the correct ball joint (Moog K6141T or equivalent) and see if it fits. The 9/16" joint will seat too deeply (Moog K6145T).

Surely a parts store will have these parts on hand to let you check the sizing of the knuckles.

I know of no reliable markings to ID a 5/8" knuckle.