Indy shop uses 12 hours as a yard stick. Dealer may use 8. Many that have posted their DIY projects on here have spent longer. Parts are about $300, includng new head bolts (a must). Machine shop gets about $200 to mill heads back flat. Eric Tyrrell has posted plenty of pix on his DIY HG and it was a trail by fire. Many others have detailed posts and pix of the work. Free shop manual in the RAVE download below.