One time, one of my idle pulleys exploded from lack of lubrication and my timing on the passenger intake cam pulley jumped 11 teeth without damaging the engine so miracles do happen. If there is damage its probably bent valves, in that case you could replace the head with a used one to save time or replace them yourself. I personally would buy a used head. I happen to have 3 heads for sale right now if your interested for an ej205, 2 passenger and 1 driver side all with good compression.