I have the Rev. You will notice an increase across the board. You MAY loose a tad of bottom, but nothing to be concerned about. But, if you ride nasty crap all day with very little need for top end, THAN a Torque might be for you. YES, the FMF will fit the STOCKER. The DF3 in conjunction with RB Carb & Head Mod will give you a much different machine. The Head will give a more consistant & higher compression than stock and RBD will modify (cut) the Slide from a #7 to a #5, bore from a 33mm to a 36mm, install a divider plate on the manifold side of the carb, to allow outstanding bottom end while allowing a hellavalot more mid & top end response. He also modify's the pilot circut to allow the airscrew to be used a fine tuning circut instead of JUST AN AIR SCREW. He also installs NEW JETS and a CEK NEEDLE.
Also, you should have your susoension (Front & Back) Modded or switch out for a KX Frontend