408 stroker with nitrous?

Here's what we did, and it's been flawless................
NOS cheater plate.
MSD timer module.
MSD retard box. Really makes it easy.

Adhere strictly to the specified rules and you'll have no problems. NOS leans towards safety in their 'suggestions'.
Pressures both on fuel side and nitrous side is important.
Good fuel. As you go up in nitrous, so too, should the octane.

We went to a custom grind from Bullet last year, and power jumped at the dyno.