Tuned a 2012 silverado 4x4 4.8L truck the other other day....it's 100% stock with the exception of a muffler-back exhaust. I didn't do anything too crazy, just disabled torque management and firmed up the shifts a tad. The truck runs better but the kid that owns it was wondering why it still wouldn't "squeal the tires" since i tuned it. I didn't really have an answer for that...was wondering if anyone else had tuned a stock 4.8? Are they just that weak? I didn't ride in it before or after, just going off what he told me.