Feigao Mix Up....I Think?

I have a Hyper 7 with a 9xl geared 13/46 and according to the speed calc it should do this:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 13
Total Voltage: 14.8
Motor KV: 1853
Tire Diameter (inches): 4.6
Tire Ballooning (inches): .15
Motor Current Draw: 0
Motor coil Ω: 0.0092
Spur/Pinion Ratio: 3.54 : 1
Total Ratio: 11.70414 : 1
Tire Circumference (inches): 15.39 inches (391 mm)
Total Motor Speed: 27424.4 RPM
Vehicle Speed: 34.16 mph (54.87 km/h)
Effective KV Value: 1853



Now the issue. I clocked this with a gps in the car at 55 MPH!!!!! I believe someone at the factory confused a 6xl with a 9xl. Has anyone had this happen before. Here is the calc with a 6xl:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 13
Total Voltage: 14.8
Motor KV: 2779
Tire Diameter (inches): 4.6
Tire Ballooning (inches): .15
Motor Current Draw: 0
Motor coil Ω: 0.0041
Spur/Pinion Ratio: 3.54 : 1
Total Ratio: 11.70414 : 1
Tire Circumference (inches): 15.39 inches (391 mm)
Total Motor Speed: 41129.2 RPM
Vehicle Speed: 51.23 mph (82.29 km/h)
Effective KV Value: 2779
KT constant: 0.49 oz-in/A


Do you guys think a 6xl will last on 4s?