Question about ordering spindles from Fatman Fabrications.

Is there anyway to tell which of the two different spindles I need for my 54 Buick without taking them off the car and sending one to Fatman? Has anybody else just ordered both sets and returned the ones that don't work on their car?

 

Here's a pic of the driver's side spindle. I'm guessing this isn't going to be able to tell anybody anything, but it's worth a try. Would it help to give them the part number/casting number off the spindle?

 

here's is the pic.