your truck is comfortable under 2500 rpm. if you naturally cruise at 70mph, find the gear that is highest, but not over 2500 rpm at 70 mph.
I think I like 4.56 for your gear set. Others will say im nuts. At 4.88 you will struggle to get to 70.
If 70 is slow, and you want to cruise faster, 4.10s.
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