YES! I gained 0.6 sec on my 60ft time and 1.2 sec on my 1/4 mile just from going from a 3000 stall 12" to a 3400 stall vig (9.5"). The only thing I'd do different is maybe a 3000 stall and the only reason I say that is my truck only drops 800 - 1000 RPM's between shifts.