Depends alot on what motherboard you have the chip in, and what stepping it is. I had a Abit KT333 chipset board, w/AGOIA stepping 1600+ Palomino, copper heatsink, 1.75v, 172 FSB, 1806 MHZ rock solid! Just play with it till it crashes, then back off till stable.
1800+ is only 1553 mhz, it will probably do that easily at default vcore=1.6v The last of the 1600+'s were the best! AGOIA & AROIA (I think?) Anyway they are all Palomino's but the later ones ran real cool and required little bump in voltage to reach nice overclocks. Check your stepping on the top of the processor, then look at the OC database to see what others have gotten. Well over 2000 MHZ is not uncommon with good hardware. www.overclockers.com