I would go with the 125/150 shot instead of a cam change.
1: alot easier to do
2: you get to keep it the same streetable condition that it is in now.
I like your thinking about for race day only. Get to the track change the plugs,adjust timing, add some race fuel and you are racing. Done for the day, put street plugs in, put timing back and on the road. I have a buddy that using the juice on his HUGH Buick Roadmaster wagon. He has added some bolt on stuff to the LT-1 and runs 14.10 on motor. He added the 125 shot and took the car to 12.99(once) but mostly 13-13.05's. Heck he even has a pic of the left front off the ground. Not much but there is daylight.
Oh buy the way, that is one ugly car. You have to be embarressed to be seen it that car. So this is what I am willing to do for you. I will trade you even up for my Chevy Aveo. You are getting the better of the deal. Performance,gas milage and a hugh chick magnet. Hey that is just the kind of guy I am, always willing to help out. I agree with 412 Stroker; that is Mag worthy.