350 V8 Gen 1 Small Block with odd leak
 

I replaced the engine in my 87' El Camino early last year with a 350 V8 Gen 1 small block crate engine (link below). I've been driving it without any serious problems, recently though the factory mechanical fuel pump was leaking and needed to be replaced. I purchased an after market pump (link below) and drove it for two days. Then the car stopped starting. Every time I turned the engine over spurts of gasoline and oil where spraying out of the sides of the block (pictures provided). The weird part about these holes is that they appear to be machined into the block (they appear to be threaded too). Thinking that I may have purchased a bad pump, I bought a second of the same pump and replaced it. Same issue occurred. I spoke with my mechanic about what was going on and he said that he has never seen anything like it.

One theory that I've come up with is that the bad pump let fuel into the oil pan. As gasoline was in the oil pan, it turned to vapor, expanded, created pressure in the pan, (this is the part that I'm guessing) and popped out some sort of pressure release plug for the oil pan.

Is it possible that I received two bad mechanical fuel pumps and just need to purchase an official GM fuel pump?
Is there some sort of pressure release system for the oil pan that uses a soft plug?

I'm really at a loss at this point and everyone I've spoken to about it doesn't seem to have a clue. I appreciate any insight or advice. I'd love to get this car running again. Thank you.

Crate engine: https://www.summitracing.com/parts/n...9529/overview/
Fuel Pump: https://www.summitracing.com/parts/c...make/chevrolet