I think they did it to get oil down to the mains quicker, on a stock motor the oil goes down the pass side crosses over in the back then runs all the way to the front on the dr side when it dead ends then the oil can be forced down to the mains, by filling the dr side with that tube as soon as the motor is started you don't have to wait for the oil to run it's normal course before feeding the mains. makes sense?