Originally posted by Pureinsanity
I recently built my 420a up with forged internals and all that good stuff.

What is all that good stuff?
You dont JUST need forged internals for 500hp. You'll need to make sure all other parts of the motor can handle 500hp and put it to the ground. You will need a built head as well, and LSD and stronger axles(you will snap stock axles with 500hp) a Good clutch Obv. and a ported IM & larger TB, as well as fuel mods such as fuel pump larger fuel lines and bigger injectors. Those are just the things on the top of my head.
But Im assuming you have something to Tune with since your going for 500hp! AEM? Megasquirt? any of those?
And for your Turbo a .50 will not make 500hp. Id go along the lines of a GTX30 turbo. Also you will want a longer runner turbo manifold, all the cast log manifolds out are not sufficient for that much power. And go with a larger enough FMIC thats sufficient for 500hp IMO Id go with a Bar&Plate type intercooler.
Im sure other might chime in on other things you will need or not need.