Solid Lifters - Race Series® - +0.8435" to 0.844" Oversize - Twin Cam | XL | Buell | M8Designed for engines with radical valve spring pressures and large lift camshaft Optimize valvetrain stability at high rpm, decrease valve float, maintain maximum valve lift, increase horsepower and torque output CNC machined and precison ground with 0. 700" diameter rollers maintaining proper and critical oil flow to top end with metered oiling Utilizes standard pushrod seat height Made in the USA Feuling recommends the use of Race Series adjustable