[FWB]

i watched the video......if those lifter rollers are flat spotted, then they were not rolling all of the time going over the lobes of the cam. i would suspect there are grooves worn into the cam and new lifters will only be a temporary fix until the cam wipes them out too....look closely at the cam....make sure the lobes don't have deep witness marks where the lifters ran on them. if it does......its new cam time....