stock losi 2.0-t clutch(green/gold with 4-aluminum shoes) and an ORION 2013 pipe..........had the same INSANE bottom end with both a 2013 and 2035(associated) pipe......temps bout 210-240 after engine/chassis is completely warmed up.....just lookin for a pinch more top end at a sacrifice of a pinch of the bottom end. but, i feel that considering hor outragious this engine is that even with the 15t bell, the bottom end will not be compromised at all...