Was wondering what supporting mods would I need to safely run 50-100 shot of nitrous, current mods are Upper and Lower Edlebrok Manifolds, Headers, BBK Throttle Body, Stage II Jet performance chip, FlowMaster Y Pipe currently running open header, I plan on only using the nitrous once every once in awhile just to give it that extra punch if needed.

Edit: It has the 5.7 350 TPI, 85k on the engine

 

What do you mean by upper and lower manifold. I don't think your motor, particularly the air/fuel delivery will supply enough fuel (i'm assuming TPI) and I think more than one or two shots and you'll have holes in your pistons..

 

the mods you have done now are already at the limits of the stock injectors. I would suggest running 24 lb/hr injectors and getting a real tune. the stock ecm cant correctly adjust for that amount of work, nor the bigger injectors. contact PCMforless.com they have excellant technical support, and they made the tune for my car, and it runs spot on with no issues