Yeah no prob. May not be the best PSU, but it will easily run a GTX660ti.
BUT! If you still need to buy the graphics card.
Consider an HD7950. Faster, better, same price and OCs like a BEAST>
I will consider it because they are almost the same price point. Just wanted to make sure my PSU can support it cause if not then I will need to but another better PSU which are true rated but I have no plan so SLI or crossfire. I currently have a HD 7770 and i think it is really good too.