The correct HTC for miners should be:

8471.41.0150

Which is:

8471
Automatic data processing machines and units thereof; magnetic or optical readers, machines for transcribing data onto data media in coded form and machines for processing such data, not elsewhere specified or included.

41
Comprising in the same housing at least a central processing unit and an input and output unit, whether or not combined.

50
Other


Also not dutiable, but that doesn't mean that they wont take it up front, and dealing with UPS' post entry department makes SCOTUS decisions look rapid.