Hack and Tap SYE
On a hack and tap SYE you cut some of the rear output shaft off, and place an adapter on the remaining splines, then drill and tap a hole in the center of the stock output shaft to hold the adapter on. Not exactly a good solution by any means. A real SYE strengthens the transfer case by using a larger output shaft, and since its shorter than a hack and tap, it allows a longer rear driveshaft. Generally a hack and tap SYE should be avoided, you get a slightly longer driveshaft, but none of the real benefits of a real SYE.