Ok so this is how it is. The stock tranny on the sv isnt good because it has so many gears, so when you get the direct drive, which is one gear, it gets rid of all the rotational mass, and it changes the gear ratio so it gives better accel and top end, i have it and love it. So if you put the 2 speed in there, it doesnt have the torque to pull it. The 2 speed is meant for the buggy, which has small tires, the volcano has big tires which makes it hard for he engine to pull, Try and put volcano wheels on the buggy and see how it goes, not good, same thing. So if you want awesome top end, get the 2 speed, but you wont have any accel, If you want the best of both get the direct drive. Im pretty sure the volcano t2 tranny wont work in the sv, but im not sure i havent looked at the t2 much. The t2 is good because it has a different tranny, and different gear ratios for a truck. These are beginner rc's so dont expect to pull wheelies, the tmaxx does because it runs really really lean, and it cost a lot more. So get the direct drive, a header, and pipe and you will be good

here is the direct drive http://allaboutfunhobbies.com/store/...roducts_id/149