Wisco high comp or 480kit?

Billy Frank (aka BillyWho) went with the stock bore high compression piston on his 03 CRF and really liked the difference. That piston and a properly designed pipe can really fill in the low end and mid-range without clipping the top end revs.

I personally like the characteristics of the 480 kit and porting best of all. It will lower the peak torque rpm by about 500-800 rpm, but for most of us the additional torque and the willingness to pull taller gears is a worthwhile trade off. The cylinder head comes from Honda in really good shape so all that is really necessary is a clean up of the throat of the ports and the area that blends in and out of the valve seats. They also respond nicely to a multi-angle valve job when it's time to resurface the seats. The only real downside to this engine is the intake valves wear fairly quickly and they can't be resurfaced, only replaced. Kibblewhite makes a stainless steel replacement intake valve and spring kit that has much longer service life and allows resurfacing of the valve in the future. The exhaust valves can usually be cleaned up and the seats resurfaced under normal use.

Ryan - You'll have to call Eric on current pricing 1-630-289-5645 .

As for the Kibblewhite stainless valves, the adjustment intervals will tend to be much longer. These valves are much less likely to run into recession problems like the OEM Ti valves do. It's a great upgrade.

The Thunder Alley pipe will be an excellent match to the 480 engine.