where can I get ahold of a 10mm step washer?
 

managed to lose the 10mm step washer that goes with my whipple idler pulley, does anyone know where I can get one of these? or if it can be replaced with something more common?

https://i.gyazo.com/e4662608812eb0c0...79a03ee574.png

My first line would be to contact the company and just ask for a replacement.
beyond that, you need more specifics about the exact dimensions of the washer. I found a few through google, but the sizes of the step, etc. are all different.
The company should be able to throw it in a padded envelope and get it out to you first class.

managed to find it and got it out with a rope and magnet thanks for the advice though!

Did you find a 10mm socket along with it?

I see what you did there:) lolz

For future...McMaster has just about everything you could need.