I think the 2.4 is a good choice if you're not looking at maxing everything out. I'm running the Lingenfelter 2.38 but it requires machining the snout. I've got the 8.66 lower on ATI damper and it makes around 16 psi of boost just for reference. The 2.4 and stock lower I think would give you all you want on a stock bottom end...and maybe more!
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'.