Could look into converting the wheels/hubs/diffs to 3.3 maxx. I believe they are made similar to the revo axles/diffs now and they hold up fine to quite a bit of power.
I run 2 nitro revos, one with an LRP28S3 in it and another with a 21TM in it. Both use stock plastic outer sliders, stock diffs, the LRP one runs stock plastic center axles and the 21TM has MIP centers (were on it when I got it used). I keep an eye on them as the yokes tend to wear over time and when I see excess stretching, I replace them as needed, which these days, isn't very often as I don't drive nitro much. Even when I did, I didn't have to mess with them much for a year at a time.
I did find that they now have diff cups with metal insert for the x-pin which fit without the i-bar the e-revo v1 had, so I bought a couple of those to have on hand when it comes time to replace a diff.