TRD Rear Sway Bar Install - missing spacer

Just wondering the group's thoughts on this:

I went to install my TRD rear sway bar this past weekend and realized I was missing the spacer for the front bolt mount. I have an email out to the dealer who I bought it from, but they're a couple of hours away and I'm hoping to get something sooner rather than later.

I'm not having a ton of luck, but plan on heading out tonight to look for a piece of tubing and/or a pack of washer that I can add in there to essentially mimic the spacing from the other side.

Is there anything I need to be concerned about? I think the washers might actually be a better/stronger option as the tubes I'm finding locally are more on the thin-walled side, whereas the spacer than came with it is a solid 1/4" thick.

Not my pic/truck, but this is what's missing:

 

Yes that spacer is pretty heavy duty, so agree with you about being hesitant to use thinner tubing. You may be able to find steel or aluminum pipe at lowes/home depot and cut it to the correct length. I think that would be suitable and would think it would work better than washers. Also check the specialty areas in both stores where they had various parts in the metal displays with drawers. They have all sorts of stuff, faseners, washers, spacers, etc. You may find something that will work.