Look into getting a new GTX 1050 Ti. Requires no 6-pin and should run safely on most good quality 300W PSUs. A heck of a lot faster and starting ~$135. http://gpu.userbenchmark.com/Compare/Nvidia-GTX-1050-Ti-vs-Nvidia-GTX-460/3649vs2167
https://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=-1&IsNodeId=1&Description=gtx%201050%20ti&bop=And&Order=PRICE&PageSize=36