Biggest concern now is lifter trash and potential bearing damage.
There is no potential damage, it's a definite with that much worn off that lifter , I'm sure the cam looks as bad.
Metal chips on the piston skirts in the vicinity of that lobe and the oil pump will be scared because it sees unfiltered oil.
Yup it's gonna be neccessary to replace all bearings, maybe rings and more. Every inch and passage of the block, crank, rods and pistons will need to be cleaned.
