I have a 2016 Ram CC hemi 4x4 Sport with the 3.21 rear. At 75mph on flat roadway, in 8th gear, my engine is purring along at approx 1650rpm’s. I have yet to order a 2019 limited and I’m split on which rear to get. Could any of you that already took delivery of your trucks, tell me what your engine rpm’s are at 75mph? I’m so curious to see how much higher it will be on a 3.92 geared truck. Thank you so much for any help!