Arcici rack fix & top plate gap distance ?
 

how much do you inflate your rack(what gap is visible)? What do you hear as a difference between too much gap and not enough? I hear a little top end extension with a little air-maybe a half inch gap thats it; pretty subtle but i like it.
i had trouble with the bottom of the box(directly under the tubes) bending downwards due to the weight. Fixed this with a friend who cut a 1x2x23 aluminum strip which went between the tubes so that screws from the side and underneath into the aluminum stabilized the box floor