8" or 10" notch

does anyone know for sure whether or not i can run an 8" notch to lay out on 295-30-24 or do i have to run the 10". i know a mag recently posted the formula to figure it out but i dont remember the formula. so i figured i would ask. it's goin on an 87 burban. thnx for any help!

not to sure but if you have them on now measure from the ground to the bottom of the frame then measure from the top of your axle to that number and add an inch or so and that will give you the size notch you need
at least thats how i do it

thanx