Precision Backplate Modification Ream your Spinner backplate to the required diameter, based on your motor Brand and Size. We even drill for engine drive pins as well! Your engine "Requires Precision Modification" to your Spinner Backplate. We will modify Tru-Turn Backplates for any R/C engine available. Please Note that it is "CRITICAL" that the bore in your Backplate be concentric and precision size. The integrity of your Tru-Turn Spinner's performance relies on the bore in your Backplate. For $ 7.50, we ream your Spinner backplate to the required diameter, based on your motor Brand and Size. We even drill for engine drive pins as well! Be sure you put "ALL" of your "Engine Information" in the Comment Block of your Order. Price $ 7.50