It is important to make sure that you have the right spacer. Different clutches, clutch drums and crank shafts need different spacers, so make sure you've got the right one when you need it. A set of spacers is available from .130"-.160" thickness or you can purchase them individually.

There are 2 different outside diameters - the .670" dia. spacers are for use with 10 tooth clutch drums only, and the .740" dia. spacers are for use with 11+ tooth clutch drums (the reference to teeth assumes you're using 219 pitch).