advice tips for increasing mhz on ip35 pro?

Hi folks, don't post much but read alot here on the forums, i hope this is posted in the correct area!

i currently have a q6600 on a ip35pro with 4x1gb team xtreeem 3/3/3/8
watercooled with 1/2 piping and temps are all good have added thermalright sinks to NB and SB.

While not a stranger to overclocking its been a few years since i really got into it (amd dut3c days!) and there seem to be more bios settings involved these days with NB voltages which i am unsure of.

basicly i am currently running 3.2 400 x 8 @1:1 and the system is solid as a rock.
set vcore to 1.32 but uguru is showing 1.28.

my two questions are :

1- with my nice tight timings on the memory 3/3/3/8 at 400mhz am i going to see any rise in performance say if i managed to get close to 500mhz with relaxed timings?

2- Aside from vcore when i start raising the mhz what are the bios voltages and settings i should be looking at regain stability when it starts to get unstable?

any tips for higher fsb overclocking on an ip35 pro greatly appreciated.