This has been covered before, however I will give you the basics.
Read everything from ClimberD. He is the god of the 5eat. He offers a Valve Body for our car that helps the 5eat hold around 350hp.
Stage 2 LGT 5eat are hit and miss depending on mileage and abuse. Transmission Coolers are recommended at the minimum for a Stage 2 set up. Anything past Stage 2 you are playing with time