Box construction notwithstanding, I couldn't bring myself to calling it heavy duty with that tower design. Even with only 41 horsepower, I think that's going to be the Achilles heel. Capacity appears a bit small too, but then maybe that's all you need - I don't know.
These are the kinds of three point setups that I'd rate as heavy duty. Weight is important too, I'd say a HD six footer should run over 700#
//greg//