Double blades on Toro WB?

After reading the post on the advantages of double blades, I would like to put them on my Toro 36" WB. The blades sit in a bracket/saddle on the spindle and I was wondering how people go around that. Do you use washers or grind a notch in the bracket/saddle? Thanks for the help

 

Is there something to make the double blades stay at a cross patern for exmark movers. I thought i heard it said once before. My blades always slide together and it is a pain to put them back again. Please help.

 

bdemir,<p>I think I remember seeing on an old post about a exmark part for holding the blades in a cross. It was made for the Exmark Viking, but the part number has been discontinued. <p>I just use a torque wrench when tightening my double blades and haven't had them move yet.