My first OC, does it look good?

I recently built a system with a core i7 920 and figured I would overclock it. I got it up to 4ghz (20 x 200) and the temps from realtemp are in the low 40's when idle and low 50's playing a game. I was suprised how easy it was, so Im just double checking I did it right.

I left QPI on auto and cpuz shows it at 3600mhz
ram is at 1600mhz
uncore is 3200
cpu voltage is 1.35
cpu pll is 1.96
qpi/dram is 1.35
dram is 1.64

I got this from a guide (obviously) which said go with dram at 1.66 but the bios gave me a warning so I stuck with 1.64 and its working. If its working should I leave it? Or could I lower/raise voltages? (thats what worries me most)

Also, do I need to run a program like prime95 to see if its actually working? Or is performing everyday computer tasks enough?

sorry for the flurry of questions and thanks

Yeah, i bet you can drop that vcore a little , but looks good.