Ok first off your ram is actuly running at 886 mhz remeber DDR - (Double Data Rate) CPU Z shows the rams base bus speed so double that and you got 886 so your ram is actually overclocked a good bit. If you really want to get better overclocks you should either unlink your ram if you can some bioses dont let you and set it to 800mhz or set it to a 1:1 ratio.
Now as for your volts you want to up your Vcore by .05 when you start to encounter instability. When you get unstable and you will you might have to go up .1 sometimes especially if you hit an overclock and windows will blue screen on startup or you might not even get past post screen. AMD recommends not going over 1.35 but you can go a little over but whatch your temps I would say dont go higher then 1.385.
And I would highly suggest not to overclock that cpu without a good aftermarket CPU cooler and some good case fans