[Dandare]

I probably wouldn't bother with carbon shock towers, as Jon says it's all too easy (& tempting) to make a part which is quick & easy to replace trackside strong ie, carbon or alloy) & end up effectively moving the weakest link to another component which may take ages to replace. Same with alloy hubs/hub carriers. I believe the rear T pieces were factory modded a while back so they may not be an issue.

I don't know what you've done to your Rat so far but with mine i fitted the ceramic diff balls & upgraded nylon idler gear (part No. AR28T)
Ball raced throughout.

I just bought a couple of the most common (but easily replaced) OE parts which break ie, shock towers, supsension arms, hubs etc.

Dave (Racingdwarf) may have something to say regarding the main diff screw as i believe he uses a different one in his Monkey due to the same problem...