Happened to find this on RC Tankwars
Bulldog / M-26 / KV- 1 Steel Gearbox & 480 Motors
HL Steel Gearboxs with the 480 motors, that drops right into our Bulldog, Pershing or KV-1. This setup is the standard gearing combine this with the smooth strong steel gears and 480 motors should make for excellent speed, power & torque. You will increase your top end speed and add the torque with the Promax 480s without the need for gearing down.
It is one of the higher cost units, at $105.00 but is sounds like a high quality product.
"Luck favours the prepared!."