I did the same thing, bought a camaro 12 bolt and the tubes were bent, torched though where the brackets were suppose to be. Anyway the spot welds on the case are some kind of Nickle or something, drill bit will not touch them. I ended up haveing a buddy with a mill and he milled them out or something, didn't cost me anything so that was cool. I think Currie will replace them check out their website.
Patrick
http://www.currieenterprises.com/CES...e.aspx?id=1190