Theres been alot of debate on the web about how safe Underdrive Crank pullies are. Many say they'll beat the hell out of your bearings, and slowly kill your engine.

Not getting into that though, and you can do searches about that matter. Since you asked, the Crank Pulley is a bear to get of the car. Unless you have access to air tools, I woudlnt even try it yourself.

Also without the crank pulley, you'd be lucky to get a couple of horses from the other 2. Most consider them more cosmetic than real power adders.