I dont know how but my stock cover fit on perfectly with the 1/2" MD space. Only one minor mod to the 2 front threads for the engine cover. Just replace them with 2 longer ones and tada! it worked like a charm for me. No drilling or hacking away at the engine cover! My friend also got away with the above mentioned but also bought 2 longer bolts for the top 2 holes =). Good luck

 

motordyne 5/16 spacer