What you are attempting is speeding. You can drive the same road for weeks at 10mph over the limit and have no worries. But guaranteed, someday, when you least expect it... Whammo, you get busted. That's exactly what happens when you over watt a psu, one day you are knee deep in a great game... Whammo, screen goes black, pc shuts off and you are now shopping for at least a psu, and a good chance of a gpu and a motherboard too.
Your call