I personally would say no. While that amount of gallons makes it sound good, the 42" long is too short.
I wouldn't either. The length is too short for the tang to have enough straight-through swimming room.
Not what i was hoping to hear to be honest
I chose the Mimic specifically because it is A) Generally a smaller tang B) Is somewhat of a grazer and C) Thought my tank would be acceptable...
I've got one in my 180 (lemonpeel mimic) in my 180 with other tangs. I would still recommend it since it is more of a wanderer/meander-er around the tank grazing, instead of darting from one end of the tank to the other. It is a really sedate type tang (or at least mine is, LOL). liveA, says a min of 70 gallons and the tang guide here says 75, so your tank should be plenty for this type of tang.
What about one of the smaller butterflyfish, such as the Latticed or Double Saddle or Dot-Dash...assuming you don't have a reef tank (although that might be why you said "No Angels").
I would love a Copperband but it'll be an LPS dominated system, hence no Angels
Thanks for the replies so far.