I've done cobra 6-6 sound great but robbs power at 80 mph range...I did the
http://www.horseapple ranch modification....
I did the stage one power kit and air filter from k/n found this to be worth-wile with the glass pack mofidication...I used a 30 inch glass pack,with a 36 in truck stack at 3.5 inchs ...can't explain it but the thing rocks out 70 to 100 acceleration is awsome... wasen't with the cobras....this year I took the recomended adjustment of clip 3 position and sofened it to clip 2 position and power hasen't changed fuel milage is up...who new....all this stuff is trial and error and right now I am rocking out and the plus side.... my 2 cents worth ....jeff gartside
towman85@aol.com out for now.........