2011 Avalanche
I went from 3:08 to 4:10. Huge Improvement in drive ability and towing. I changed the speedo with Hyper tech and was ok but trans shifting was off and soft. I tuned with Black Bear and now is great. Shifts great and much more power Now I drive in D instead of manually holding in gears to stop the constant shifting up and down. Tow mode better too. I tow a 7000 trailer and in 5th at 60 is about 2200 RPM.
I would definitely change the gears and tune again.
2200 RPM at 70 in 6th with 17 inch tires
Also installed Derale trans cooler with fan cause the trans runs hot in these even with no load in the mountains etc. Put it between the grill and radiator tight fit but works good.
