8 1/4 u-bolts

I am doing the same swap and purchased 8.75 shock plats and u bolts they measure
3.5 inches from center to center. I am pulling 7.25 out of my 68 cuda and putting in
the 8.25 sure grip . my 68 car is at my shop so I cant measure the U Bolts on the 7.25 . I made the purchase based on what I read here in different post . Was hoping
others would chime in . I will be doing the swap soon and will know more then. But
everything I have read here says you need the bigger u bolts and shock plates and that the 8.75 ones will work on the 8.25 rear end but 7.25 will difinitly not work as they are to small. Cheers.