Approximately how many hours are involved in replacing a head gasket on a BMW E36 engine?

I'm about to start on this project and am wondering how long it should take. Other vehicles it's around 8 hours. Is this reasonable?Approximately how many hours are involved in replacing a head gasket on a BMW E36 engine?http://www.pelicanparts.com/bmw/techarticles/101-Projects-17-Head-Gasket/101-Projects-17-Head-Gasket.htm i hope this will help a little, i think the time is quite reasonable from past experience.