Getting ready to purchase a Vortech V3 setup for my GT. I've read a lot of different threads on various forums about the OPG's, and when to replace them. Only looking to make 575-600hp as this is my daily driver. I didn't have any intention of taking it past the stock 7k redline. Shop quoted me around 900$ for the OPG installation - a fair amount of change, just wanted to see if it was truely worth the expense.