The best way to think of nitrous oxide injection is to understand you are adding a fair amount of combustion pressure and temperature. Estimate your naturally aspirated horsepower and torque and then add your nitrous kit to that.
If you currently have an honest 350 horsepower and you add 100 horsepower (actual increase, not the kit suggested power), and you use it for short blasts of fun without complete traction and under about 5500 to 6000 RPM you will probably not have any issues with your stock rods.
If you currently have, let’s say 450 horsepower and you add 100 horsepower your stock rods and rod bolts become questionable.
If your stock rods were rebuilt with ARP rod bolts, I would not worry about it at that nitrous level.
You also did not mention the rest of your combination, so everything is guesswork. Do you have forged pistons or hypereutectic pistons? The hypers are brittle and should not be pushed hard, but at 450 hp total you would likely be ok if ring gaps are not below specs.
