I need a 170 left hand crank for a mongoose triple MTB. The tricky bit is that when the crank is held at 12 oclock position the square taper hole must appear as a diamond. All good quality cranks would appear to set the hole as a square, only the cheapest of the cheap appear to do otherwise, there may be obvious reasons for this. Black is preferred but the only essential criterion is that the hole is sound and not worn.