When I pulled the engine on my 1650 to upgrade the engine cradle and iso mounts, the engine had 4 approximately 1/8” spacers around the bolts between the engine Pan and the cradle. Are these stock or some kind of an upgrade done by the Cub Cadet Dealer when the engine was rebuilt about 12 years ago? I plan on using lock tite around the 4 engine bolts along with lock washers. Not sure wether to put the spacers back in or not. Thanks for any advice.