Futaba is one of the best brands in Servos adding the 9373 and 9372 version intended for 1/8th scale Nitro Racing and unveiled at the Dirt Nitro Challenge in 2016.
With over 341 oz/in of torque and .06 sec transit time at 7.4v, the 937X servos are top notch. Titanium gears, Dual Ball Bearing and programmable via SBus2 makes these even better. The 9373 adds a full aluminum top cap and ears for the best durability.
Here's where I got them and some info from Futaba:
9373 Aluminum Top:
FEATURES
Programmable and compatible with S.Bus and S.Bus2 systems
High voltage handles extra speed and power provided by 2S LiPo
batteries
Can be connected to a PC using the CIU-2 USB adapter sold separately
(FUTM0951)
Full metal case
One year limited warranty through Hobby Services beginning at date of
purchase
INCLUDES
S9373SV S.Bus High-Torque HV P.G. Car Servo
1.7" (44mm) 3 Arm Servo Horn
Two Rubber Grommets
Four Eyelets
3x8mm Servo Horn Screw
SPECIFICATIONS
6.0V 7.4V
Torque: 280oz-in 20.1kg-cm 341.7 oz-in 24.6kg-cm
Speed: 0.07 sec/60° 0.06 sec/60°
Dimensions: 1.6 x 0.83 x 1.43" (40.5 x 21.0 x 36.2mm)
Weight: 2.7oz (76g)
9372 Plastic top:
FEATURES
Ideal for 1/8 scale off-road vehicles
Engineered to handle power output of LiPo batteries
Compatible with S.Bus and S.Bus2 systems
S.Bus2 functions can be programmed using the CIU-2 USB interface
(not included, order FUTM0951) and downloading the free PC link
Metal middle case section
Titanium gears and dual ball bearings
One year limited warranty through Hobby Services beginning at date of
purchase
INCLUDES
Futaba S9372SV Servo with Wire Lead and Connector, 1.7" (44mm)
3-Point Horn, four Eyelets, two Rubber Grommets, 3x8mm Horn Screw
Instruction Sheet
SPECIFICATIONS
6.0V 7.4V
Torque: 280oz-in 20.1kg-cm 341.7 oz-in 24.6kg-cm
Speed: 0.07 sec/60° 0.06 sec/60°
Dimensions: 1.6 x 0.83 x 1.43" (40.5 x 21.0 x 36.2mm)
Weight: 2.7oz (76g)