7 1/4 to 8 3/4 swap in A-body

I just checked again, (it's pertinant because we are going to do this to my son's car in a few days) axle centerline to pinion u joint centerline for the 7 1/4 is 10.09 inches, 12.35 for the 8 3/4, difference is 2.26 inches or .010" more than 2 1/4 inches.