Caster and vibrations

Here is what I have found so far;

1) I have 2 bad wheels.
2) The toe out is measured at 5/8 inch.
3) Caster is 5* measured at the bolts on the diff center. Actually, the top of the diff is furthur forward than the bottom.

Corrections to date;

1) Replaced the defective wheels.
2) Adjusted the toe in to 1/16 inch.

The front drive shaft is still dissconnected and the vibes occour at 75+ MPH.
Late last year, I made and welded on a lower control arm bracket to the driver side diff replacing one that was busted. I have no unusall tire wear and have very good directional control and stabillity.
Is there something I am doing wrong when measuring the caster ? Is it possible to measure sides at the ball joint in the drive way? Money is a little tight at this time.
TIA.

What you have measured is pinion angle not caster angle and the top should be further forward. You can convert this to caster angle but you do not say if you have a low or high pinion Dana 30. If it is a low pinion you add 9 to your negative 5 ( your caster is the other side of vertical ) which would give you a reading of 4 degrees. this is a bit low depending on how much lift you have. Stock is closer to 6.5 degrees which would read -2.5 off the diff. If you want more detail on this look at my site.
As your drive shaft is off it is unlikely to be your caster causing the vibes and could be anything in your front end like worn tie rod ends to worn control arm bushes. It might not even be coimg from the front but even the rear!

Thanks Gojeep . I looked at your site but did not pay enough attention to the formular. Now I know where I am. All I have to do is get to where I should be. I did put a few more shims (packers) in. Boy was I wrong; and by the way, I do have a high pinion D30. I will let you know how it all turns out. (After that we could talk about how we West Indians will whip your buts in the game of cricket) :cheers: