i bought 407`s vrt last year. i broke that box in weeks,put another standard one in and got another month til 3rd went again, then bought sparks box (see post in this thread) that he rebuilt,with treated internals and a new peloquin and it has lasted well,even with my lead foot and 23 psi whooshing through a .63 housed gt3076r. 440bhp and it still works fine,