RE: The next step
What about the rest of us happily running HLs, that havent tried to put too-big of a motor in them, that run them everyday just fine -- did we "get what we paid for?". I think we got a whole lot of tank, for not much coin.
Oh, and "Why shouldn't it take the same motors" -- have you compared the cost of a HL S&S board (made for 380/385) to a Tamiya DMD unit (can do up to 540) ?
If you didn't attempt the failed motor swap, you'd still have your HL running around right now.... you cant blame Heng Long because you put an "out of spec" motor in one of their tanks