I put one in for my trip to Los Angeles. The engine had bad cam bearings and it helped mask the related noises. I would not reccomend them for anything.
The fit is an easy one. The idler gear must be measured in, and compensated for. It is simple. Put some clay on the idler, but the cam cover back on, and grind the difference between the cover, mark left, and specs. Simple.
Gear drives are the most annoying, miserable things to drive with I have ever experienced. Kids stuff. Stick with a chain and you will not have to change it later for a chain.