pop off valve

from what the machineshop that makes my manifold says its something you absolutely want a backfire is a pretty meen hit to the rotors in the blower,strong enough to flex the rotors far enough to make them hit eachother and the blower case if this happens you will ruin both the rotors and the case.
this is what i was told,but im working with a twinscrew wich has supertight tolerances to seal real well without any kind of stripes or any kind of metal in contact with anything else.
im going with a popoff valve and nomather what i think it may be better to be safe than sorry :)