i think i'm just gonna buy a bleed valve!
yeah, that probably best mate ! get a brass lockable one from stu at motorsport developements, very reasonable price and also as its brass theres no expansion under heat, plus theres a locking nut on it so no one can tamper with it etc....
when you fit it, probably best to do the above mod as well (drill & tap etc..), boost should be spot on then
Duncan