New to 12 valve please read and help

Ok i just bought a new to me 12 valve yesterday. It is a 1994 model 4 wd single cab 5 speed with 80K original miles. I have owned a 2009 model, 2001 model, 2004 model, and a 2006 model but never a 12 valve. The truck is in new like condition. It had had some work done that i will list but i have no idea where to go next with the truck. The goal is 500 hp and thats the max i want. It has a southbend clutch, cold air intake, 5x14 injectors whatever size that is, number 10 fuel plate, 913 pump with extensive pump work with delivery valves worked, stock turbo. It smokes like a train and has pretty good power but i am not sure where this puts me as far as how much power i have now and what i need to do to get to 500hp. Please forgive me for being dumb about all this but the 12 valve seems to be a different animal than i am use to so i need educated. Thanks