Measure from center of the crank to center of cam and call Webber Racing. He'll hook you up with what you need provided the measurements are correct.
Heres how i did it.
Measure from the very bottom of the crank to the top of the cam using a dial or digital caliper.(you may have to pull the cam out slightly to get the caliper on the cam surface that rides in the bearing) Then measure the crank diameter, divide it in half and subtract it from the crank to cam distance. Do the same with the cam, measure the diameter, divide in half and subtract from the crank to cam distance. Subtracting half the diameter will put you right in the middle of botht the crank and cam, hence giving you the distance from the center of the crank to the center of the cam.
It sounds confusing but its actually pretty simple just hard to explain. HTH.