If you run a box with boost fooling on an '04. 5 and up with the electronic WG, you have to run a new boost source (from a boost bolt or whatever) to the WG to control boost. If you don't you can hit 50psi or more since the PCM never sees high boost (because of the box fooling it) so it never opens the WG. Just by installing my TST and leaving it set on 0/0 I could hit 45psi boost without a proper WG boost source. With a manual boost controller I have run as high as 8/5 with boost solid at 35psi.