Great find! I could really have used that a couple of weeks ago. Will it work on the crankshaft pulley too?
Here's the older thread that mentioned this tool:
Cam and Crank Pulley Tool
Even though I had my radiator out, none of the many impact wrenches a friend had in his shop would fit — they were all too long, even with the shortest socket. We searched online and around town for a short-throw impact wrench, but couldn't find one.
Ended up doing the "wrench holds one camshaft pulley bolt while you loosen the other pulley" trick. A little scary, because I wanted to re-use my timing belt, but it worked out OK.
Others have used that trick, but with the old timing belt just prior to installing a new one. When you
know you're not going to re-use the old belt, you can even lock it tighter onto the cam gears with vice-grips.
I used a strap wrench to re-tighten each cam pulley without too much difficulty.