LT's & ory performance problem, plz HELP!
 

Well, my '00 Z28 had edelbrock shortys and a flowmaster 40 ser. muffler when I got it, I gutted the cats as well. I just recently installed pacesetter long tubes and a 3" off-road y-pipe.
Now the exaust note is powerful but too raspy. There are no exaust leaks or rattles. Will a resonator take away most of this raspiness and help bring back the deep tone it had? If not, then what will?
Also, I immediately noticed a decrease in power! Is this due to a lack of backpressure? When I get a good tune in it will it dial them in right? Please help!

-Brian