2.5/4 Drop Tubbed with 22x14 Rear wheels fitment?

[DieseLife]

I have a distant customer asking us about tubbing his 1972 c10 to fit the widest 22 in the rear possible without getting into the frame. Has a 2.5 front and 4 rear drop. Otherwise stock.

EDIT: Talked him out of it due to tire sizes not being available for what he wants. Now hes looking at 20x12 or 22x14. So im rewording my question torward a 22x14 clearing with just tub work?

Thanks