What effect would you expect to see by fitting a Turbo Exhaust on an N/A?

I aquired a secondhand backbox to replace my one

(due to the flange completely corroding away), and i suspect its from the Turbo engine as the outlets are slightly larger and the flange is 50mm or so further to the right of the car

(toyota is stamped on the body though).

I dont expect any gains in power, I just dont want it to be overly noisy

(or loose power).

Cheers