I am taking a motor apart to prep it for new Heads and a cam.

When I pulled the fuel pump off the side of the motor ( a mid '70's to early '80's 305) a mix of gas and oil spilled out from behind the pump plate. The oil was definatly full of gas because the puddle evaporated to just oil after about 20 minutes.

When I drained the pan to take the timing cover I noticed a faint smell of gas in the oil.

So, did the pump actually leak gas into the engine? or did the fuel get in there some other way?

Is this a common failure? The pump is a newer remanufactured unit, but it does look cheaply made.

 

Yup, it can pump fuel into your oil when it goes bad.

 

Yes. Used to pretty common years ago. Good that you found it before it got serious.