Well, I finally sucked it up and pulled the intake manifold on my 81 380SL. All the rubber stuff is hard as woodpecker lips so I'm replacing EVERYTHING in search of a vacuum gauge pegged to the left. Whoever posted that the intake manifold bolts are a beotch knows what he's talking about. After about four of the bolts' allen heads spun out internally, I learned a Craftsman 12mm 16pt 3/8 drive socket will drive on the bolt head and get enough purchase to bring it out. I learned Kroil and PB Blaster will not penetrate down to the threads in the head, even after THREE WEEKS with impact and heat. I only wrung off one bolt and was able to drill it out. I chased all the threads w/8mmx1.25 tap and will use new MB bolts to go back together. Should I use any anti-seize on the bolts? THANKS to this outstanding forum for the info and encouragement you don't even know you give me. At last I'm able to give a tip; sorry I don't have an account to post pics. THANKS - Stan :bowdown: