If your brother has a supercharged Tibby, and you have a boosted Tibby (turbo?), just turn up the boost a little bit or find some efficiency somewhere (tuning maybe?). Stripping out a street car is lame, and adding a few extra HP is more worthwhile than losing all of your interior and creature comforts.

Make sure you have some light wheels, good tires, and a light flywheel. Lighter flywheel is cheap acceleration, so are light wheels. Good tires will let you put all the HP you make to the ground, obviously. Make the most of what you have before you go nuts getting rid of everything that isn't welded down..