What do you mean start better? Do you mean starting the engine or spooling the turbo? A 68 turbine is not very fun on the street with a low compression small displacement V6 engine. You need approximately 1200 RPM more stall speed at zero to have the same spool up as your old stage III cheetah
That may work ok at the drag strip when launching with 10+psi but from a roll it will be very lazy. I recently was able to back to back my 6265 with a 68 turbine turbo and spoolup was much slower. From a roll without kick down about 2 sec longer. Night and day difference.
You'd be better off with a smaller turbine and the correct torque converter. This way spool will be good on the street and the turbo will support the interned power level. In addition to the stall at 0 you need to know the stall at full power to be able to get the most out of what you have