That is a question with no definite answer... Another reason I can't say is that I don't have a Rusty, so I have no idea how strong their tranny's are... My Epic 18 (before porting) tore up the idler gear in my RC10GT with ease... on the other hand, my cheap Tower ST15 ran the Epic longer, with a tighter slipper, and never got torn up. Amsterdamn's Evader had an idler gear torn up after switching to a Wasp 18...

In all cases a hard gearset is available, but other things too have an influence. We run our slippers TIGHT, because our trucks stay on the street (the Savages are for off road) and keep our diffs tight as well. These things are hard on the tranny and not how you would set up something that runs off-road....