i just did that on my truck yesterday. if you are talking about the float assy. you can pick it up at oreily or autozone for about 25-30 dollers or you could go over to Rockauto.com and do a search for your vehicle and they will ship it to your door
also, while you have the tank down you might want to check the pickup unit (black plastic with a screen at the bottom) to make sure that it is not brittle that piece you have to buy at the dealer
good Luck,
Kevin