Here is what I am doing. I am tuning my second truck 01 lb7. I down loaded a tune from DP. The OS is differant so I downloaded a stock tune with the same OS then ran a script. Then ran that script over my stock tune that has a differant OS. Is this right or am I going to cause problems because of the cal.? numbers being differant. I think I did it right but need to be sure.. I AM LEARNING AS FAST AS I CAN GUYS. just an old wrench guy