heres how I run my 3500+
fsb 235Mhz, mem 333 setting, that gives you a mem speed of around 400 and a clock speed of 2.6Ghz.
You will probably need to set your cpu volts to 1.4v.
pci locked at 33, agp at 67 (or pcie at 101)
htt to 4x (from 5x)
disable cool and quiet
everything else auto
try setting the ram at 3-3-3-8 cl2 for starters with its default voltage.
then try cl1, then 2.5-3-3-8, then 2-5-5-7 (these will probably need 2.8v on the mem, thats within std.)
run a complete memtest-x86 between each change (~30min/Gb)
then when thats done prime95 it for 6-8 hrs