If the valve seal stuck to the stem during the downtime it may have torn the seal.. also if the valve guides were knurled by your machine shop or replaced with brass guides they may have cracked a guide and this will allow oil into a cylinder.. But that thing is burning RICH!! and thats enough to keep a cloud of eye burning stench alone... Have you added antifreeze yet? You can smell the obvious sweet smell of antifreeze when it burns. same with smoke, but fuel is the one that burns your eyes the quickest..