waterpump pulley.. interchangalbe with 5.0?

I recently found out that a waterpump pulley is a rare item or sumthin.. autozone, kragen, and pepboys dont carry them..neone no where to get one fast?? another question i had is if neone noes if the 2.3 waterpump pulley is the same.. my engine came without one so i cant match them up..but my 2.3 has two pulley's on the waterpump.. a big one and a smaller one.. Does neone no if one of them is the same as the 5.0's?? thanks