Stock Ecu limits
 

Unfortunately I live in Ny where obd2 emissions exist. My 04 msm is currently at 160k miles and I've found my lower timing cover is cracked and leaking. I have a BNR 16g turbo that I've yet to really see its potential. What is my best bet for forged internals where I can still swap back to my stock ecu every 2 years to get an inspection so I can reregister the car. My goal is to see around 280-300whp. Will I have any issues running supertech 83.5mm forged pistons 9:5:1 with manley forged h beam rods on the stock ECU for approx 50miles every 2 years if I put stock injectors back into play to pass inspection? Any help/input on what route to go is appreciated

Assuming your ring gap isn't as loose as Hustler's behind, forged internals in a vacuum won't have any effect in terms of your stock ecu being happy.