Agreed with the other guys. I think your trans will be fine at your power levels. My first two days, I used Sport mode and let the car shift for me so I could pay more attention to driving; now I use manual mode so I control when torque changes to the wheels. Have fun!
2009 Hot White G8 GT, CTS-V v1 fronts, Camaro 20's, BMR Sways, Eibach Springs, Rear Cradle bushings. GXP FE3's, BMR rear susp. Kooks 1 7/8 LT headers, RCR custom 3” exhaust, ported LSA blower, 2.38 pulley; Ported heads and TB; LS7 MAF, Racetec pistons, Scat rods, CTS-V crank; FAST 85 injectors; RCR Lunati cam: 219/237 .612/.601, 114 +2 LSA. CTS-V pump/VaporWorx cntlr. Built trans, Methanol injection. Rick Crawford built and tuned. Best 1/4 9.68 @142, 1.42 60'.