Dann, and zzman
I've been running the stock idler gear in mine for 2.5 years now and never had one strip out
So long as you don't hammer down the slipper, and have it adjusted right, the stock plastic idler is fine. You just replacew them when you replace the diff gear anyway. The brass idler is a safty net for those that like to lock down the slipper/diff

Hows the water down under, safe to swim?