[spreader]

Safe, I dunno, probably not. Certainly not the correct way to stretch a frame. A number of welds; well, just about all of them, looks as if the penetration is not there. If the front end is good and you can get another frame why not re-do just the rear half. You're going to have to stretch a new frame also. This time use a 'Z' cut or a 45* bevel cut. Take about a 1' section of this crap frame and cut off either the top or bottom so you have basically a piece of 'angle'. Place this piece inside of frame centered over the weld joining the two halfs. Either drill and bolt or 'rosebud' weld this inner & outer frame together. This is basically the correct way to stretch a frame, but a lot of people just use a diamond shape fish plate either on the inside or outside.