Which Spindle goes where?
Your spindles really don't care which is a "left" or which is a "right"
They can be installed on either side.
It depends which way that you want to mount the calipers.
Facing forward, or facing the rear.
Figure out which way you want to install the calipers, look at the spindle(s) and you will figure it out.
What spindles are you starting out with?
Disc brake spindles from a donor car.
Or drum brake spindles? 9 inch? 10 inch?
I may have to change my answer, upon knowing what your working with.
