I need to replace the intake manifold plenum on a 98 Regal. As I understand, this is a problem with these 3.8 engines. Is this a job a person with average automotive skills can likely do successfully? What problems can I expect? I see there is a ?hidden bolt? reference on the existing plenum. What?s that all about? Where is the best place to buy a good quality replacement? The most complicated job I have successfully completed is replacing a cylinder head on a 96 Escort. Any advice would be greatly appreciated.