I took my manifold to get milled flat today, I am getting a new gasket as well. My dad suggested to put some light coat of silicone around the intake port on both side of the gaskets. Thoughts? Is that a good idea?
If it isn't too late, It would be a good idea to replace the gasket between the intake and exhaust manifolds, then install the bolts and nuts back in loosely, then install the assembly back onto the block without the gasket that goes against the block.
Tighten the bolts which goes into the block snugly, then tighten the nuts and bolts which hold the intake to the exhaust manifold.
Then you can remove the intake/exhaust assembly off and have a good baseline for your machinist to do an accurate milling operation for your specific block.
While doing this procedure, you might get lucky and find that the replacement of the gasket between the intake and exhaust manifold, in addition to leaving those nuts and bolts loose until after you tighten up the bolts which go in the block will eliminate your gap issue.
Use a thin feeler gauge in several locations between the manifold and the block.
