2 piece to 1. Lip Seal???

Im replacing the 2 piece vacum shafts for the one piece and had everything broke down and ready to install and found i have the wrong seal for the diff side. i have a regular lip seal but i was told i needed a seal with a flange if not the seal i have would just slide its way out. i found some part number from previous threads but i cant find the actual part:dunno:. ive tried google search the numbers but i come up with nothing. does anyone have a website where i can purchase the seal or does autozone sell them and thier part number?