There are charts on the web for cross referencing Champion spark plugs. Sparkplug-Crossreference.com uses a search tool that allows the input of the Champion plug number to return a chart of equivalent plugs from other manufacturers.
Other sites, including Nology.com and ProGreenGrass.com, feature charts to cross reference Champion spark plugs for automotive and small engine use. An effective cross reference can be done on automotive parts websites like advanceautoparts.com. A site visitor specifies the vehicle year make and model, followed by a search for spark plugs to returns a list of all available plugs for that vehicle, including Champion and its equivalents.