wha mods do you have? stock? beefed up lightly? bolt ons?? give us a lil more room to work with here, give us some details...
if you just saying in general, then 50 should be fine... basic bolt ons 75-80 [used in moderation]
beefed up internally, who knows how much it could handle...
ask kurt gordon [used a GSR though], he knows alot about nitrous cars.... same with my buddy eddie who is also known at bakersfield as naturally nospirated... ran a 2.0L LS Motor on a two stage system squeezing out about a 230 shot!!!