Lower Ball Joint taper dimension VS spindle ID

[fishnixon]

1968 C30 Conversion project underway...C30 drum to disc.

I've put in 1986 P30 ball joints into the control arms.

I called my local salvage yard, and explained I was looking for a 73-87 2WD C30 front spindle-dually disc set up and they said they had one.

I picked up the whole front end, cross member and all, and once home, I commenced removing the spindle set up. At present I have one spindle seperated from the discs as the discs need help (turning) or replacing. I stopped after looking at the one spindle and comparing to my ball joints all ready in the control arms.

Here's more set up for my questions...The O.D. of the lower ball joint at it's widest part is 1 1/8 inch and the I.D. of the respective spindle location is 1 inch. I believe that a 1/16th on either side is a lot to overcome to get the spindle onto the ball joint. Is this a normal measurement and I should continue the project and place the spindle onto my new ball joints and crank it down? Or should I look for "new" spindles? I do not want to scar up a +$65 lower ball joint without confirmation.

Could the salvage yard parts be non 73 and up and have a smaller spindle/ball joint orifice? It is a dually set up for 2WD that I picked up. Is the P30 ball joints different than a C30 of the same year, 1986?