My wipers "chatter", no matter if the windshield is wet or not.  I had the blades checked, told they were okay.  But I also have read that this is a common problem with Corvettes and one fix was to use 3 or 4 blade wipers.
Any comments, suggestions?

If the windshield is clean (no coin car wash waxes-spray waxes-RainX etc.)....my guess is even though the blades may "look" ok....the rubber may be harder because of age. Usually a chatter will stop with new softer blades.  As a general rule cheaper/discount blades are usually noisier. JMO