Just changing the head, assuming the same loft and that the loft is right for you, would not make a difference. Both drivers are recent enough to be similar in the face dynamics. However, if the Sim2 is larger or has a higher MOI, off center hits might go a little farther. Generally, all we can do with the specifications of a driver to increase distance as we get older is to go lighter in overall weight and longer in club length (although not too long to make so you can’t hit the center of the face). Of course the loft of the head and the flex of the shaft need to fit your game. You want the lightest, longest driver that you can control matched with the right loft and flex to maximize you distance off the tee. You can also go to the gym, but that’s a different approach that is not something many of us will commit to, I know. Getting the lessons was an excellent way to start getting you back on track to hitting it your best. A tweak of your driver specs plus your more efficient and improved swing gives you the best chance to gain a few yards.