If you're tearing into your HR (07-08 350Z, 370Z) engine to do any service that requires removing the timing covers, you'll quickly discover what a nightmare it is to remove all the grey RTV that Nissan uses to seal them. Depending on how much you feel your own time is worth, it may make more sense to just replace them. No cores required, but we suggest using a metal recycler for the large amount of aluminum you have in the old parts. This does NOT fit the VQ30DE engine found in the earlier 350Z models. Only the HR engine!