I have just discovered that my exhaust manifolds gasket went, blow by at the block. I have removed manifold, no cracks looks good. However one of the bolts securing the manifold to block was gone........ This is before I took anything apart. The bolt sheered off, now drill and tap seem to be my only way on the install. Can anyone tell me if the bolts from the block are molded with the block, or are they screwed in at factory. I'm talking about the bolts for securing intake and manifold? Another note.... Where the bolt was sheared off is where the blow by was accruing. My car has all original parts and only has 30,384 miles on her. I love this car so much, and I am desperate for some help by anyone whom is willing to coach me through this repair. Mind you, I'm no mechanic, but have good hand skills, and some know how. Thank you very much.