So tonight i removed my 3.21 gears and open diff and installed 3.92s and trac-loc. It took me about 5 hrs. and i am happy as hell on the performance change. I lost the third gear bog and am sure to lose a few tenths of a second in the 1/4 mile. I am going to go to the track in a week or two and see exactly what it does. I have had a personal best of 16.0 with not many prior passes in my life. I have high hopes for mid 15s i feel it has it in it. I guess time will tell.