We have used wood bleach on a few cars and 3 wheelers
https://www.google.com/amp/s/amp.reddit.com/r/motorcycles/comments/34ac18/need_to_figure_out_the_best_way_to_clean_rust/
The rear end floats and moves a lot on a 510 especially when you run higher spring rates and double the power. If your under 150 hp you don't notice as much
I was thinking a 323 gtx trapazoid set up would work . But the diff is to small. The rx7 rear end is almost the same . I thought you wanted to try that?