90Deg Rotation on Adjustable belt tighener

After the Tension block in http://www.thingiverse.com/thing:194586 refused to cooperate, I went looking around and found http://www.thingiverse.com/thing:181349 (kudos to cahorton) as a substitute. However, I needed the block oriented 90 degrees and rewrote the scad slightly. It could use some cleanup, but seems to work just fine.