Rear Leaf Slotted Shims: Longer Bolts/Washers Needed?

So I ordered some 3° shims, to fix my vibes @ ~20mph, and I didn't realize were slotted type.
Like these here:


I'm running the newest style Dakar rear leaf pack w/stock bump stops. Must I add washers or a longer leaf pack bolt to run these? The $10 spacer seemed odd to me as I've never ran any type of spacer w/shims before. Also, the $10 spacers don't fit the new style Dakar leaf bolts.

 

When I did mine, I used the non-slotted spacers. After my research seemed better for me. I didn't want it to slip out at all. I did measure the stock Dakar center bolt and added the thickness to the spacers, for good measure. I went and bought new stronger "Allen Head" center bolts, easy to use and keep from spinning or scratching up a round center bolt with no head.

 

Added. If it's too long after, you can cut it easily.
I also think that slotted is cool but I wanted peace of mind

 

I intended to buy the type you did.

 

Which center bolts did you go with? I may need to go this route also.

 

Wheelers IIRC

 

I forget right now I'm at work.. It's a easy to find size bolt. The place by me maybe Granger, had some. If you had to. Wait until you get the packs. Clamp, remove bolt measure,, buy locally or online.. Just try to get a harder than average bolt