Hi,
GW started phasing wood out of their boats a couple of years ago. My understanding that in 2015 GW has no wood in the transom or stringers. I believe it is still used in decking and coring applications.
From their website.
All composite structural components. There is NO wood in the transom or structural stringer foundation of any newly built Grady-White. In fact, Grady-White utilizes an impervious-to-water, high density, closed-cell polyurethane foam reinforced with woven roving and continuous strand fiberglass as the basis of our structural stringer systems and transoms. Furthermore the sturdy composite transom on each new Grady-White is reinforced with a solid aluminum transom angle brace to distribute torque and provide unfailing strength. And even though it's not required for boats over 26 feet, each and every Grady-White of every size has enough sprayed-in foam flotation to ensure that the boat is unsinkable. No boat brand has better certified flotation characteristics.