I have a corsa quick & quiet on my 7.4 mpi, under the flapper is a plate with about a 1" hole in it for the exhaust to come out. can I drill out the rivets and remove this plate with out any problem with water getting into the exhaust?? I know that this will make it louder

I did this on mine about 20 hrs ago and had no problems.

how did it sound and did you pick up any rpms?

it improved the sound but no perf. gain