When replacing the water pump or engine front cover on 429 and 460 cu. in. engines watch gasket placement. The water pump can be installed with the gaskets in the wrong position, the result will be a severe external water leak between the pump housing and the engine front cover. The pump gaskets should be installed as follows:

The gasket without tabs must be installed between the water pump cover and the water pump housing.

The gasket with the tabs must be installed between the water pump cover and the engine front cover.

(P52)