Water Pump Plate?

Ok here it is... Working from pump to motor:
1. the water pump
2. a pump-to-"plate" gasket
3. a thin (brass?) plate (it and the pump-to-plate gasket are not removable due to the way the impeller is mounted onto the shaft)
4. a plate-to-engine gasket
5. another gasket and im not sure what it goes to. im sure ill figure it out once I get started tho, this is gonna be my 1st slant6 h20 pump swap!