UM, MS is old school. There is a gear in the dash that operates that.
Would require custom gear, lol.
55/70-16 265/75-16 Difference
Diameter inches (mm) 30.06 (763.4) 31.65 (803.9) 1.59 (40.5) 5.3%
https://www.tacomaworld.com/tirecalc?tires=255-70r16-265-75r16
Speedo Reading Actual Speed
20 mph (32.19 km/h) 21.06 mph (33.89 km/h)
25 mph (40.23 km/h) 26.33 mph (42.37 km/h)
30 mph (48.28 km/h) 31.59 mph (50.84 km/h)
35 mph (56.33 km/h) 36.86 mph (59.32 km/h)
40 mph (64.37 km/h) 42.12 mph (67.79 km/h)
45 mph (72.42 km/h) 47.39 mph (76.26 km/h)
50 mph (80.47 km/h) 52.65 mph (84.74 km/h)
55 mph (88.51 km/h) 57.92 mph (93.21 km/h)
60 mph (96.56 km/h) 63.18 mph (101.68 km/h)
65 mph (104.61 km/h) 68.45 mph (110.16 km/h)
So yeah at 65 I was doing almost 69