I'm thinking about replacing my current 5.3 motor with LS3 6.2L . What has to be done with the computer for this set up to function with my truck. Thanks to GM great 07 flex fuel motor I'm burning almost 1.5 quarts of oil every 1000 miles. What I here from the dealership is that is normal for that motor to do that. Any gm mechanics know how I can get them to stand behind the motor?