Help TC won't drop in place

It's obvious in the picture that the splines are different but remember this, the coarse spline input shaft is a smaller diameter so a fine spline converter (such as your new converter) will drop in it, it wouldn't work but it'll go in place. An old style coarse spline converter will not drop onto a newer fine spline input shaft. I can see the splines down in the converter well enough to tell it is a fine spline so it should go in. My guess is the problem is either what Kim said about the pump gears aren't lined up right or for some reason the pump bushing is too tight. It's possible the rebuilder buggered up the bushing installing it. When I rebuild one I always clearance the converter snout/bushing so it goes together easy. You don't want them real tight either cause the bushing gets hot and swells up tight on the converter and that's real bad. I'd first try what Kim said about aligning the gears. If that doesn't work take it to the rebuilder.