I think an engine replacement will raise questions, but if the new engine is well documented it will probably raise the value, especially after some time and mileage. If you immediately try to sell it I do think you’ll take a hit, as new buyers would be skeptical and less willing to risk...
I would replace all of the coolant hoses and clamps, thermostat, heater T's, vacuum hoses, fuel filter, PCV valve/hoses. No matter the miles, all of those parts have a lot of years on them, and they aren't expensive.