Swapping 8.75 in place of 7.25

Hello folks, hopefully someone can help me out.
I am swapping a 8.75 in my '75 Scamp.
I found out The axle centerline to yoke/universal centerline is 12.35" for the 8-3/4" axle.
What is the axle centerline to yoke/universal centerline measurement for a 7.25?
I need to know how much I need to shorten my drive shaft.
Thanks for your help!