Intake Manifold

I believe that is the DR30 Skyline intake manifold. The differences other than runner length, I cannot say. source

If your changing the head gasket, just disconnect the exhaust manifold, and leave the intake on. You can pull the head up enough to get the head gasket on without even taking the head out of the car, just might need an extra set of hands or something to prop it up while you prep the head and block for the new gasket. source

From what i know, the PI intake is okay even in the upper 300s. Good grief, guys spray on the stock manifold and get into the low and mid 400ft lbs tq. source

I may end up going with the FAST after all, because of stuff I'm reading about the typhoon having bad fuel lines or something like that. I just hope my local mechanic would be able to handle the install, because I need to have some "adapter kit" added for it to work with an LS2 engine. source

Keep in mind that a stock fuel rail will support up to 400 hp. So unless you just want it to look good stick with a stock one. source