FYI, hobbystar HS-4320hv on sale at rcjuice, $30

[olds97_lss]

Usually $40. I have a couple of these in service the past 6 months or so. One in my ERBEv2 pushing around 3.8 trenchers and one in my outcast with the stock backflips. The servo does a nice job in both, especially on 7.2V.

https://www.rcjuice.com/hobbystar-hs-4320hv-hv-high-torque-digital-servo.html

Specs:
Specifications:

• Speed @6.0V: 0.17 sec
• Speed @8.4V: 0.16 sec
• Torque @6.0V: 337 oz/in
• Torque @8.4V: 416 oz/in
• Pulse/Frequency: 1500µ/330Hz
• PWM Voltage: 3.3V-5.0V
• Dimensions: (LxWxH) 40.5x20x40.5mm
• Weight: 62g
• Bearing: Dual ball bearing
• Gears: Steel
• Motor: Digital Core
• Input Voltage: 6.0V-8.4V
• Output Shaft: 25T spline
• Wire Harness Length: 260mm

I made a video of it a while back when installing it in my ERBEv2 in comparison. Skip to 2:10 to see it at 7.2V. At the time, I thought the max6 put out 7.4, but later found out after posting and didn't want to remake the video. I updated that in the comments.