In 1998 grady had fully transitioned to rot resistant plywood for the transom and stringers in all boats. I've followed this website for about 5 years and have not seen a single post about structural rot in stringers or transoms in a 98 or newer model. I'm sure some will eventually have issues, but nothing like some of the earlier models.
Based on the dimensions, I would assume the 247 uses the same hull as the 248 and would have similar handling characteristics despite the 248 being heavier. That said, a 225 ox66 pushes my configuration well. 2 adults, half tank if fuel and we can hit 44mph. The 225 ox66 makes a lot if torque compared to most if not all 4 strokes with the same hp rating. Don't let someone lead you to believe it is not enough power till you try it.
Good luck
