I installed the JL line mod in my truck without a chip and could not tell much of a difference in the 1-2 shift but the other shifts were noticably firmer.I then installed the JL chip and the truck shifted so hard under normal driving conditions that the shifting was annoying,the dash would pop and felt like something was going to break under the truck.I sent the chip back to JL( was also pinging)and he fixed everything.Good strong shifts,chirps tires but still a good daily driver.If i had it to try again i would just try a chip at first and then go from there.