Hmmmmm- - - - - -just misplacing that bolt is not the cause of your power loss- - - - -the consequences of doing that are far more serious. The oil that lubricates the rocker arms passes through a metered hole in the bolt, which means your rocker arms, and the shafts they run on have been running without lubrication the whole time since the rebuild. They have obviously tightened up, and were trying to stall the engine down. Unless the shop has completely dismantled the rocker arm assembly, inspected all the parts, and repaired/replaced anything that's been damaged by running dry, they haven't corrected their mistake completely. DO NOT accept anything less than a full teardown, inspection, and repair of the top end.
Then there's the issue of where all the displaced metal from running the valve train dry went- - - - - - -Good Luck!
Jerry
