I was under the impression that the aluminum master cylinders that are popular on our cars don't have any bias built into them, but they do have two different volumes for each side of the reservoir which is why the rear port is supposed to go to the larger volume system on the car.
Not all alum master are biased.. my 3/4" master isnt but
a lot of larger masters are.. you would need to check
what you have.. mine has the larger side also.. I have
a couple of alum masters that are the same size.. I got
a FEW masters when I was working in the brake lab( I was
on loan to the brake lab but my room mate worked there
all the time)
