bolt size for uniball

i was wondering if a 1/2 inch bolt would be to small to use on a fullsize for upper im using a 7/8 uniball with 7/8 to 9/16 misalignment adapters at the moment but cant get enough angle out of it the stock upper is giving me better results

The thing about 7/8" sphericals is that they don't offer very much useable angularity. If you found that the 1/2" misalignment gave you the angle that you needed, you could weld the lower misalignment spacer to the spindle. That way, there isn't any load on the bolt itself.

Make sence?

ya thats what i was plannin on doin anyways...saw your pics of the taco spindle. the hole in the spindle now is of course tapered but the 9/16 bolt almost fits the smallest portion of the taper what would i do with that..a spacer? i could drill the spindle out and put a sleeve in it

The only thing that you need to concern yourself with would be centering the spacer on the spindle. Don't worry about the bolt hole size too much.

so as long as the spacer is welded straight on center theres no need for some kins of spacer in the hole on the spindle the load on this area must not be alot just for added concern i could drill the hole out and put a metal spacer in the spindle right

Right.