Heres some simple facts...
if you go water meth you will have to be re-tuned for water-meth combination this will be a stop gap measure as it will only help when your under boost since these generally only work during wot or once the maf voltage reaches a certain level, generally under load during wot.
Meth will on average reduce your IAT temps <which are totaly different from your engine coolant temps> by about 40-50degrees. This will result in horsepower increase in itself but if not PROPERLY tuned for it will cause a rich fuel mixture. Now the downside to this is that if you tune for this combo and you run out of meth your fuxxored.
You need to intercool that thing. If im not mistaken you got the cheap vortech unit which if im not mistaken is designed to run between 8-10lbs of boost. Yes it will make more but it leaves its efficiency range which results in added heat. Sometimes more boost isnt always better.
There was recently a 95 gt at TDS that went from 10lbs to 13lbs on his vortech and the car actually lost power due to the added heat from being out of its efficiency range and especially with no innercooler. With iat's as high as they will hit on setup like this any sensible tuner would pull timing to keep the car from detonating that you would end up loosing power. But sometimes you cant explain this to people its like
The engine coolant temps are best around 170degrees this is where most of these cars are designed to run and generally if they are cooler than this they will actually start to add fuel into the mixture. This is like when you crank a car you have whats called cold start fuel trims which add more fuel to allow for ease of cranking as well as help the car heat up. Alot of your good tuners will keep a car over nite to allow them to dial in these factors as well as others such as hot starts , idling, drivability issues and all these good things.
moral of the story meth isnt going to be the godsend you or others think it is.
You need an intercooler and need to turn the wick down some but then again dan shouldve already told you this