Try the 4.56 gears and see how they do. They should be close enough to make some passes. My guess is that you'll eventually need to swap in the 4.30 gears as you get used to the car and the power. You have enough power there to run high 8's at over 150 mph so depending on the converter slip you'll be spinning the motor pretty hard in the lights with the 4.56 gears. Depending on how well the chassis works and how good you are at tuning the engine you might eventually need to drop down to a 4.10 gear. You'll just have to work the process and see where you end up.