rear upper shock mount extensions

Hello,I moved rear end towards back of car 1 1/8' on 68 Dart to get tire clearance,now I need to figure how to extend upper shock mount about same towards rear to mount upper shock bolt,anyone tried this before? I changed front spring mount /hanger from 65 B-Body to move rear back,able to fit 265/75/15 tire to get look I want,thanks