Need help choosing a junkyard engine

first thing to look at is the milage on the car it is in. then you look for things like new gasket sealer on items like oil pan, valve cover, timing cover and such. if you find one that looks like it has been all apart, it probably has, you might have a rebuilt engine there. sealer on the timing cover alone could mean a new timing gear and chain. pull the heads if you can, your gonna do 'em anyway. and go thru the glove box under the seats, and in the trunck for recipts and clues, alot of empty oil bottles are a bad sign. tune up parts boxes are a good sign. look at everything on the car not just the engine, it will tell you what kind of life it had. overall i would rather have a one from a 4 door granny car, than a duster sport with big speakers and mag wheels.....unless the sport had been rebuilt.