MBX6T: more steeringpower

[Gv288]

Hi, currently I'm running a MBX6T CC2200kV Mamba max ESC on 4s 6500mAh
With Mike's conversion kit. I have heavy Maximizer Beadlocks on it with, again, heavy 40-series Mashers.

My current steeringservo is the HITEC7955, which puts out 24kg (333 oz./in.) torque on 6V. After doing some research it seems that the ESC puts out 5.1V to the servo. So I have effectivly 24kg x 5.1V/6V = 20.4kg (283oz./in.) torque (is this correct?)

Anyway, it's not enough. So I can go for an external BEC, but I'd rather not.
So I'm looking at this servo: Hitec 7980
http://www.hitecrcd.com/products/dig...hs-7980th.html

Which put’s out: 38kg (500oz./in.) on 6V, does this mean: 32.3kg (425oz./in.) on 5.1V?
dimensions: 43.69 x 22.35 x 39.88mm (1.72 x 0.88 x 1.57inches)

The questions: is my reasoning correct on the torque VS volt, and will this servo fit Mike's conversionkit??
Thanks