What gear ratio running 65mph @1350rpm with and 18 speed
I just bought a 2014 389 peterbilt with a isx 550 Cummings, 18 speed RTLO-20918B with DANA-SPICER D40-170 40,000 lbs full locks and 3.91 ratio on 22.5 tire. My question is. What gear ratio should I have to run 65mph @1350rpm in 16 gear or 17gear. Thank you
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