No. Couldn't be bothered quoting all the wrong bits.
Anyway,
If you intend on running a relatively small shot (most people run wet kits on their skylines), of about 50-75hp then you can simply run the right spark plugs and retard your timing a little bit.
You absolutely do NOT have to have forged internals to run nitrous. Think about it this way:
You have a stock motor - If you fitted a bigger turbo than stock, bigger injectors and manifold to suit and made an extra 100hp over stock you'd have a certain amount of extra pressure/load on your internal components, (rods, pistons etc).
Then if you take the same stock motor, add enough nitrous to make an extra 100hp, you have roughly the same load/pressure on the internal components as with the bigger turbo.
Just remember, making more power in an internal combustion engine can only happen by burning more fuel with more oxygen. Nitrous Oxide use introduces vast amounts of oxygen so you can burn more fuel - just like a bigger turbo, camshaft change, air filter change etc.
Hope this helps. To see the results of a stock motored R33 gtst running a small shot of gas click here: http://per4mancevids.com/2rismo_11.9.mpg
Adrian