There VALUE depends on the condition. They usually leak around the valve stem holes. Remove the stems (just cut them off from the inside) and inspect the machined holes for corrosion. If they are badly or even moderately corroded, they are indeed scrap. If the stem holes look good, put them on www.craigslist.com and maybe you can get a few bucks for them. They will fit other GM cars. List them by their size, 16 X 7 or whatever they are…You can e-Bay them too, but shipping will cost more than they are worth…