piston and cam

[400EXdude]

hey my 2004 400EX has a White brothers E-Series slip on and is properly jetted...i was thinking about getting a Stage 1 hot cam...and a wiseco 11:1 piston...my question is how much more of a power gain would i get...would i have to change the jetting...and if you have any ideas on top speed that would help too thanks..

[cals400ex]

you will get a very nice gain. you may need to go up on the mainjet one size or so. the top speed won't change too much without changing the gearing.