Front Wheel Cylinder bolts

[tbucketnut]

Working on my 64 1000, noticed something really weird, the bolt size that attaches the wheel cylinder to the upper spindle bracket is different size left to right side. The driver's side the thread size is 3/4", the passenger side is 9/16". Anyone care to venture a guess why the different sizes? This is original because the upper ball joints have never been off the truck (riveted) so I know the spindles havent been changed through out its lifetime.
Things that make you go hmmm......
Steve

[AZKen]

Don't the spindles come off without de-reviting the ball joints?

[tbucketnut]

Interesting thought Ken, and yeah, I guess it would but if you wanted to R&R a spindle, I would think you would replace the upper and lower ball joint because by the time you got it apart, chances are one or the other ball joint would be buggered up, dont you think? I inspected both ball joints today after the pickle fork was used and it was gouged up pretty good, I wouldnt reuse it and the rubber was destroyed too.

[AZKen]

I know what you are thinking and using logic but the least logical is the factory used two different spindles. BUT I'm not sure if you have two different anchor bolt pilot sizes or thread sizes........... or whether you have two different hole sizes in the wheel cylinder ears.

I have a pump but don't know what a oldsmobile style is. PM if you want to see pics.

[tbucketnut]

Thank you Ken for taking your time for responding, really appreciate it. First the easy, the wheel cylinders holes were the same, both new and old and big enough to fit the larger bolt. The actual bolt thread size is 3/4" for the driver's side and 9/16" on the passenger side. So each spindle was drilled and tapped to those sizes. I have a thought, maybe because my truck had the factory power assist it puts more force on the hinge points of that spindle necessitating the larger upper anchor point???? I'll get some pictures to attach.
Thanks Steve

[AZKen]

Could be but it's usually cheaper for a factory to have the same parts (bolt). The good thing is that it will all go back together.

[jagarra]

Makes you wonder if one of the spindles was replaced in the past with one from a 3/4 ton model.