If you look at the pictures of the cover that goes over the case opening there are two bosses there. One sticks out 1″ from the flange, and the longer one is 1-1/4″. The key to making this fit is to use the adjustable offset engine mount (sharkshifter one is great) and move outboard until you run out of sprocket/chain clearance, and move the motor back so that the hump on the starter nose clears your seat. Another potential help would be if you happen to run an offset engine sprocket which will let you move it outboard a hair more. You can also use low profile head bolts on your third bearing mount.
With the weight I have to add for KM, I have recovered my L/R balance.