Trying to iron out new suspension/wheels/tires

[downbytheriver]

Just want to make sure before I start ordering:

I currently have a 68 stepside that will lowered in the front with a 4.5" ECE kit. The back will be lowered using air bags.

My plan is this:

15x8 front, 4" backspace 235/70/15
15x10 rear, 4" backspace 275/60/15

I do not want the wheels sticking out past the fenders. Also, I would like the widest back wheel I can without sticking out from the fenders. Will this work without rubbing? I do realize I will have to trim the LCAs slightly. I researched for hours today, and just want to make sure this all will work before I spend the $$. My brain is fizzling out