So I had a 09 4 door 4x4 Chevy 1500. Had stock 3.42 gear ratio I think with 7.5 Rcx lift and 35s. The 6 speed transmission couldn't find the right gear on interstate running 70mph. Kept going from 5th to 6th constantly. So I sold it.. my next truck was a 2007 1500 with 3.73 gear ratio and 4 speed automatic transmission. I installed a 5in Rcx lift and 33s with no problem ran great on interstate. Now I'm looking into lifting my current 2009 Tahoe which has the same running gear as my previous 2009 Silverado. Is there any suggestions I can do so that I don't have to worry about the freeway issue. I want to run 35x12.50r20s. Possibly re gear? I want to be able to drive it long distances on vacation. Thanks btw this is my first post. Hope it's in the right place

 

I think lifting it you would want something geared down a bit anyways. I'd go wtih 3.73s.