If using nitrous you will need to everything that you can as far as head gasket sealing goes.
The factory crank is a tough item - I would consider getting it Cryotuffed or Nitrided.
Rods should survive a pretty harsh environment - they are forged from the factory. You could get them linished and shot-peened.
I would recommend steel flywheel and perhaps a Romac harmonic balancer.
Tuning it on the fly with nirous etc is inviting a disaster.