Hi Mike,
I had to lower my engine to remove them (mostly for the left one) but I had washers between the block and motor mount which raise the engine a bit (for Derale fan clearance) and roller rockers. It should be doable without lowering it if you have stock rockers, and the Tiger covers have no fins on the rear-most couple of inches for extra clearance. It wasn't difficult to lower it, just be careful putting the fine-thread bolts back in that secure the motor mounts to the frame (I loosened the bolts holding them to the block to make it easier).
-Jon