Will be watching/reading thread closely as I had read somewhere that meth is no good on a PD blower.
I know Vengeance Racing uses meth on a lot of their builds and I highly doubt that they have any issues with a meth kit as they are still continuing to use them. (I know I am talking apples to oranges as far as engines go, but it still serves the same purpose.)
I believe Willie is a fan of this guys Meth injection system. From my understanding, to do it correctly you need to make an injector nozzle system that feeds after the blower. the bottom plate of the lower intake manifold is a good place to drill and tap nozzles. 1 per cylinder is recommended for even distribution of the methanol/water mix.
From my understanding, having the meth injected pre blower will not provide sufficient cooling to the air charge. It will help with detonation control, though not as well as feeding each cylinder individually. A dyno tune is highly recommended.
A Vampire knock control system should be considered if you have an 07-09 GT500 as they do NOT have knock sensors.