Roger that! I did that even before I soldered up the esc. Credit goes to the members here for pointing the issue out so I could address it before becomming a problem with my truck.

I kept the stock 2mm rubber spacer for some impact cushion than added 4mm of solid spacers for 6mm total.

I first tried fuel tubing but it flexed too much for me and would have required over 9mm to keep from over stressing the outdrives. I didn't want to limit uptravel any more than I had too.