Rear Shock Mount

I just finished moving my differential back 1/4" for bigger tires (69 Barracuda). If I moved it back an inch the tires would definitely hit the back of the fender lip!! I also moved the lower shock mount forward 1/4" and it worked out perfect. Make sure you weld it real good and put some gussets on there so that you don't crack the welds!!
Also, I don't think you change the pinion angle by moving the rear end back or forward but your driveshaft may not have enough engagement into the tranny if you move it back an inch???

Treblig