Hot Rods So-cal 37-41 round spindles

So I bought a set of repop 37-41 round spindles from so-cal, and I need to shave a bit down to fit onto the lincoln backing plates I got from WilsonWeldingMachine.

Before I get to grinding, I wanted to make sure I shaved the right side down. Is there a top and a bottom?



Does it matter? Couldn't find anything in the search. Sorry if this is a dumb question.

 

Absolutely matters. If you bolt it onto the axle it will be very obvious which is which.

And if you don't want to do that, the longer of the kingpin bosses is the top one. It accounts for the kingpin inclination (leaned in at the top).

 

Thanks Anderson.

Longer kingpin boss up top; got it!