brushless conversion help!

[ransom]

i have two savages one is 4.5 kg 10.? pounds
one is 5kg 11 pound
without batteries is that heavy or light
here is the speedcalc for the heavier one i only run 4s

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1.5366847826086956
Other Ratio: 1
Spur Tooth Count: 49
Pinion Tooth Count: 13
Total Voltage: 16.00
Motor KV: 1900
Tire Diameter (inches): 5.84
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 3.77 : 1
Total Ratio: 19.15855 : 1
Tire Circumference (inches): 18.35 inches (466.01 mm)
Rollout: 0.96:1
Total Motor Speed: 30400 RPM
Vehicle Speed: 27.57 mph (44.28 km/h)
Effective KV Value: 1900
KT constant: 0.71 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

savage 2nd cog