J
You said in your opening post that the car was very fast so why are you going to change it before you even raced it? The best advice anyone can give you is only change one thing and only one thing at a time. When it comes to different weight of drivers, you might want to raise or lower ride heights.Just remember that spring rates are constant, no matter how much you wind or compress the bars or coil springs.
Bobby Layne
2014 Midwest Lightning Sprint Champion