You can use a 3/4" bolt. I did this on mine at first, although it doesn't fit well in the stock bushing.

Do you have a bench vise? If so, you can do like I did. Press out the factory stud from the factory hangers. Drill a 3/4" upper hole on one half of your custom shackle then weld the factory shouldered stud into it. The other half of the custom shackle will need a 9/16" hole, as will the rest of the holes for the lower.

If that's confusing, let me know and I'll try to describe it better. <img src="/forums/images/graemlins/cheers.gif" alt="" />

[color:"darkgreen"]1986 4Runner - 4" IFS - 63" Chevys - 33" ATs - 5.29s - Rear Detroit
Sliders - Kayline - Rebuilt 22RE - On Board Air AND Factory AC
www.xtremefabricator.com[/color]