Engine run/ break-in stand

Curious if anyone has made a run/break-in stand, I'm looking for options. Im making this stand now, for a 360 I'm building for my 69 Dart. Everything is adjustible the motor mounts adjust, the only thing thats specific is the holes for the bellhousing I have unistrut with spring nuts for the rad. support so it will work for any motor, all I have left is to put together the control panel.