There are many guys on here running the 4K rpm tune with only head studs, valve springs, bigger turbo and the fueling. Pushrods aren't really a big concern but if your in there then you mite as well toss them in... I'm building my motor for 4K rpms without boring the cylinders or putting a thicker gasket on. It's only gonna see 3500 when I pull it. The extra 500 is if anything breaks and the motor wraps up before I can let off the throttle.