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?
The only thing fed from the left side on a BB is lifters. The theory is oil is rushing through the right side so quickly, as it has to feed the mains AND the left side from the end of the right galley, that the oil can't make the sharp turn to the main feed passages.
My theory is, plug or drastically reduce all the dang leaks so the oil isn't rushing through the system, squirting out all over the place, and can keep the crank full and under pressure.
High RPMs is where the issues show up.
