280 sunsport cruising speed

Own a 99 280SS with twin 350 mags. Only 120 hours, runs beautifully and fast - 60 mph. Sweet spot is about 3500 rpm @ 38 mph. Below that, she gets sluggish and wants to drop off plane. Is it possible to cruise at 30 mph? Because of the twins she's stern heavy. The bow rides a little high...