Burl discovered that Titan Tires still carry Goodyear 4ply Terra Tires. http://www.titanstore.com/info/XTR396

Burl writes, The tires are actually made by Titan Tire; Titan bought the molds from Goodyear. Most listings will only list the 8 ply but there are 28 of the 4 ply tires available if none have sold since I purchased mine.

The fellow to contact is Terry Nagel. He is the factory rep for Goodyear. When I inquired about these in the beginning he checked inventory on the 4 ply and he found 31 each of the 4 ply in, I think he said Cleveland but I could be mistaken on that issue, and are available.