a lingenfelter(sp??) is a 43,000$ upgrade from a ls1, basicly just a motor that was designed by john ligenfelter, who is now dead fyi.
http://www.supercars.net/cars/375.html this is a 2000. there is no noticable different between this car and a reg zo6 other then it will pass you up faster! if u pull up beside a vet, it could be a lingenfelter!
http://www.supercars.net/cars/3231.html this is a 2006 anniv edition, even meaner. NOT STREET LEGAL.
thats a car!!(specs on right side of pg)