Those puppy's make a LOT of heat. If you had to add a heatsink (and you might) it wouldn't be worth the cost of doing it. Make sure you add some thermal grease. What M/B or chipset? LX,BX,etc? Does it support 100Mhz? If possible up the bus speed to 75. That will give you the more improvement over changing the multiplier but the multiplier might be easier.