The HAPP Ultiumate Joysticks allow you two heights using a provided spacer (one about 1/2 longer than the other). As someone said above, if you are using restrictor plates as well, which add about 1/4 inch you would really need to route a 3/4 MFD. If you aren't using restrictor then you should be fine not routing the 3/4 and using the joystick at it's longer length (if you go with HAPPS).