Elk antlers do not need to be split but you will pay for an oversize bag which will be about $150-175. I flew American last October with a 370 class set and it was absolutely painless and they arrived with me in top shape. I completely covered all the points and most of the beams with foam pipe insulation (bought at Walmart in NM) and duct taped the heck out of it. Check with the airline you will be flying before heading to your destination and print out the rules in case the person at the counter doesn't know how to handle the situation. Have your ducks in a row and you shouldn't have too big of a problem.
Jason