Back in 80 I was changing the ball joints on a 60 Apache 10, needed some more room under the truck. So I put a bumper jack on the front and raised it as high as I could, when I heard it hit the wall of the garage. I am walking today because I had jack stands under it. Of course the stand is a little shorter than the other one. Both my legs were under the front end,while I was beating on the rivits. Always use caution after that,Was only 19 when that happened.
