As you can tell from most of the responses-- if its the engine longevity your concerned about- you should have ZERO worries. I too have had several reliable testimonies saying well in excess of 350K and still running strong. Again-- if its the engine your worried about- look it over physically and drive it and listen to it - running first @ idle then reving it easily in park/ neutral, and then running under load. I would not worry TOO MUCH about a leaky engine, those are for the most part easily fixed by changing the valve cover gasket which is very do-able ( even a sixty year old clown like me did it fairly easily ). If the valve cover is leaking it will make it look like you have a rear main leak also ( mine did )
funny how the rear main stops leaking when a valve cover leak is fixed
Good Luck