I was wanting to modify the rear spindles on my car, but the inside of the univeral yokes on the spindles had large deep holes. This keeps me from the modification, for it would greatly weaken the shaft, only because of the approximately 1-1/4 dia. hole, about 2" deep from the outside face of the yoke. This is a 1987.

Are the 1984-86 spindles also having the large deep hole on the yoke side? Are there any afermarket spindles available that could be examined?

 

I wasnt quite clear on what youre asking but it sounds like youre more or less talking about the yokes themselves and not the rear knuckles.

Vette Brakes and Products had aftermarket splines/yokes for the earlier C3's but not sure about the C4's.Havent seen their latest catalog yet.
Maybe they have something for you.
What did you want to modify? Just curious and sorry if I misunderstood your post.
:)

 

The part that we are desiring to modify is the spindle that drives the rear hub.
We would like to move the rear hub about 1/2 minimum farther onto the spindle. To do this we were looking to move the shoulder on the spindle back that same amount. This would probably break into that hole on the yoke side of the spindle.

No that i am discussing it, I wonder if indeed the spindle is made in two pieces, and then the yoke welded on? That would explain the hole in the yoke? I'm here at home now, no way to verify that. Anyone know?

That being the case, I could machine the yoke off, and get another set of spindles and machine the shaft out. Machine the length narrower in the yoke. Machine chamfers on the ID of the yoke, OD of the shaft. Heat shrink the yoke on the spindle shaft. Weld within the chamfer. Finished Part?

This would be even better, giving me a full spline for mating within the hub assembly

Anyone know?

 

Fast,
What youre explaining to do is way out of my league and probably for alot of us here as well.I dont even remember seeing a post here to shorten the shafts and rear end suspension assembly since the past 2-3 years or so Ive been online.

Im almost under the impressions you want to shorten the parts to fit a fatter tire inside..am I right so far?I coudnt imagine why else someone would shorten anything unless they wanted to get some big tires in there.

As far as the spindle yokes go, Ive had mine off the car before and it doesnt look like it was welded together at all but a one piece machined yoke/spline for the U joint and hub.
Then again Im no engineer so I cant say for sure,but the machined finish was smooth top to bottom with no indication it was 2 pieces which is why I thought it was machined on one piece.

Just wanna say good luck in what you end up doing...maybe Jegs or summit racing will know how to fix you up with your mods...Btw,are you trying to mimic a 4 link like suspension by modifying the stock IRS?
Sorry I couldnt be more help here.
:)