I'm not certain, Jeff would have better first hand experience... I'd love to know what the cruising RPM and MPG are at 70 MPH running the 4.88s and 235/85R16s.
I've seen it mentioned that the 4D56t/D4BF tends to enjoy revving more so than the earlier 4D55t, as well as most diesels in general, but that fuel economy starts to suffer significantly beyond +/- 3000 RPM.
My person experience with 4 cylinder Japanese motors indicates 3000 RPM is a healthy general ceiling for longer, sustained use to keep the motor happy and efficiency up.
I'm intending to run a 4.636 / 235/85R16 combo with the V5MT1 in order to cruise at 70 mph while spinning +/- 2,850 RPM; anticipating optimum MPG to be achieved somewhere in the 2400-2850 RPM (60-70 MPH) range depending upon externalities (temps/wind/terrain/load/etc):
View attachment 566128
V5MT1(3.918/2.261/1.395/1.000/.829) / 4.636 / 235/85R16(31.7"),
https://www.blocklayer.com/rpm-gear.aspx