That is strange I don't know if I would grind on the block I would be more inclined to grind on the exhaust manifold first. If I screw this up at least you can find another one. you should just save up and get a set of headers, they are a lot easier to work with, only that center bolt is a pita but you can do it. The engine wants you to switch sides with the manifolds and put on a turbo kit.
Be careful griding anything off the head. Use a straight edge to be sure there is actually a high spot on the head. Did u straight edge the manifold?
Took a bit off each. Installed timing cover exhaust manifolds and pan today. Time consuming. Thanks for all the help from everyone.
All in the name of hot rodding. Make sure to repaint those areas on the block to prevent rust, not that you'd see it.