Caster shims

Hi, I have a lowered 68. A mate gave me some caster shims to help the ride. Do they go behind the top or bottom spring tube?? Cheers

Behind the top tube would give negative caster, behind the bottom would give you positive. I would think you would want to make it more positive.

Yep, bottom tube for sure, I'd hate to think what that car would be like to drive with them behind the top tube! Also you might think about a bigger anti-sway bar.