Wossner forged pistons for KTM bikes are the exact same height as your stock cast piston on the intake side. This means you can still tap your crank shaft on your 300 and blow up your bike. You can purchase modified Wassner pistons from bestdualsportbikes.com or pinitracing.com, which are cut on the intake skirt. Only these won't blow your motor. Cut stock pistons yourself or purchase these ones from either of the above websites already cut.