your fuel pump wont need to be changed, my stocko is running my V8 with nitrous, there a pretty good standard pump, You will need to do the gearbox as yours will probably not handle the power as well as the diff, depending on how u drive, i broke 3 diffs with the rb25de though so maybe im a little harsh on the car. theres not much else u need, brakes can be an afterthought and dont need to be done straight away nor does the suspension. Ive had the V8 in my gts with stock suspension for almost a year now, its a little soft but u can make do with it.