Does any one have an AS rear block with the Firestone ride rite system? I am looking at doing this, probably one and then the other down the road. The AS rear block is 3 inches and does not have a bump stop, like the factory 1 1/5 block. The problem is the Firestone bags sit on the bump stop, however you could install it like a 2WD truck which doesn not have a block. Then the problem is the airbag sits 3 inches lower then it should and will not work. Luckily Firestone makes air bag spaces in 2 inch increments, what size would I need 2" or 4"?