About: http://webisa.webdatacommons.org/396097913

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	you didn't mention if you where referring to and original aluminium cover. if so they are casted, where the steel ones are stamped. and also aluminum is a more expensive material.
http://www.w3.org/ns/prov#wasQuotedFrom	hotrodders.com