TOP TIP -
To stop the rear tyre dragging on the shock bottom joint when fitting a high speed modified motor which will ballon the tyre much more than the stock motor.
Remove the rear mudguard completely or cut away the screw boss from below, you'll see where your tyre will have marked it! You could try spacing it up with small washers if you want to keep the scale appearance.
Also, cut a flat on the shock rod end to match the profile of the swing arm and improve clearance to tyre, as here... (Blue Arrows)
While you are at it, (Red Arrow) glue a piece of scalpel blade or similar hard thin metal sheet to the swing arm where the droop screw touches it, to prevent it punching through.