Here's what I did, with the same CPU. Intel E2160 and the same motherboard Asus P5N-E SLi nForce 650
the motherboard I was using was a little upset that I had my OC @ these settings
CPU 1200
RAM 800
now usually that would be ok however it said no no No!, so i put up with
CPU 1066
RAM 800
for a long time which effectivly gave me a clock of 2.4GHz from the initial 1.8GHz stock, everytime i tried jumping up the FSB even after re adjusting the voltages I still couldnt get past the bios splash, so heres what I did...
I jumped my Vcore to 1.3V
I jumped the RamV up to 1.2V
I jumped the Ncore to about 1.23
I lowered my multiplyer from x9 to x8
clocked my CPU from 800 FSB to 1333 FSB
clocked my Ram from 800 FSB to 1000 FSB
lossened the timmings from 4-4-4-12+2clock to 5-5-5-15+2clock
now I run @ 3.0GHz with 1GHz Ram with a slight increase in temps though not drastic by any means, all with stock air cooling out of the box it came in,
so you see lowering the multiplexer and using the method of adjusting the FSB to a compatible rate will allow you to make a tasty overclock.
not bad for a £350 build, hope this helps mate.