Yeah. The EcoDrake (1.28gpf) tank is model number ST743E, and it will fit on your C744 bowl. If the toilet is relatively-new, you most likely already have the Eco bowl (C744E), because that's the bowl Toto now uses for both the 1.6 and the 1.28 version of the original Drake. If you have the older 1.6 bowl (C744S), you might see a difference in performance with the 1.28 tank, primarily because the 1.6 bowl starts with a little more water in it and the refill percentage on the fill valve might give you a little less than a full bowl to start with, but you might not. And all of that can be tweaked with our help if you need it.
Before you go buying a new tank, you might as well just pull the old tank and reinstall it. Maybe try new washers and/or tank-to-bowl mounting hardware, and follow our instructions for mounting that tank. I.e. position the tank over the bowl. Holding the tank level, slowly tighten the bolts, alternating one side then the other after just a few twists, and watch the three points of contact get closer to each other. You may need to loosen and start tightening again if one seems like it is going to touch well before the others. Tighten until the points of contact are almost but not quite touching, like you could slide 2 or 3 sheets of paper in between them. That's good enough, and the doughnut gasket that the tank sits on should be well enough compressed to keep the tank from wobbling. Don't ever tighten once any point of contact on the tank is touching the point of contact on the bowl, because if you tighten once the china touches, you will likely crack something; porcelain doesn't compress when pressed against porcelain. The best tank-to-bowl set of hardware has two bolts, and on each bolt there will be two rubber washers, two nuts, and two metal washers. The first rubber washer goes under the head of the bolt inside the tank, and the metal washer and nut go OUTSIDE the tank on the bottom to hold the whole thing in place. The metal washer does NOT go inside the tank, despite what 1000 handymen will tell you. It just doesn't. Then, when you put the tank on the bowl, you use the rubber washer, metal washer, and nut, all under the bowl, to pull the tank down towards the bowl.
If you think you have a little leak around the bolt head and rubber washer in the tank, we recommend lightly sanding the bottom of the tank around each bolt hole with some very fine sandpaper, to smooth out any little imperfections in the floor of the tank so the washer makes a good seal against the porcelain and prevents leaks.
Hope this helps. Come back with any questions.