I just saw a small drip of fuel at the back of the motor, it looks like it is dripping out of the trans bellhousing.

What are the main culprits that could be leaking back there? I am newer to PSD, but not overall to diesel trucks.

Truck is completely stock other than a Superchips tune.

 

probably coming from something around the fuel bowl.

 

or one of the vitron fittings is going bad on your fuel line. need to track it down .

 

Ill put money on the fuel filter drain valve o rings