...Going for 100mph are we?
They both broke? At the same time? Wow. Congratulations!!....*ehhem* I've snapped a whole bunch of the pins, but never broken a drive cup. About the only thing that would surely be stronger would be to use a dogbone setup. There are a few ways to convert the Rusty axles to dogbones- just search the forums and they'll turn up. Or hopefully someone who knows will just post here...
*edit* Oops. The FLM's are dogbones. I need to
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