Currently looking at 2016 Prius V FIVE with 70k miles. (The vin says it’s 2017 but the title says it’s 2016) I was wondering if it worth to buy or there might be head gasket issues.
you have the advantage of the upgraded pistons and rings, but the jury is still out on the cause of the blown head gasket. at 70k, you are hopefully in time to clean the egr circuit before problems develop. you can't control past maintenance, but you might want to consider 5k oil changes and more frequent engine coolant changes, or at least ph testing
EGR system has a propensity to gradually but inexorably clog up with carbon. Seat-of-pant DIY’rs, my self included, think “that can’t be good”, and clean it. My 2 cents: every 50k would be optimum. A lot of owners, not unreasonably, consider that onerous. But here we are, with Toyota working as hard as possible, to dodge responsibility. see first two links in my signature, for EGR cleaning tools, tips and tactics. On a phone turn it landscape to see signatures.