Changing out the manifolds and risers on my 4.3l volvo penta was a task I keep putting off. I finally got around to pulling the manifolds off and bought a set of mayhew gaskets scrapers for the task of cleaning up the mating surfaces on the heads. The port side came out really well as I had just enough room to work with. The starboard side was a different story. I had to work blind and couldn't hardly get a good angle to scrap properly. Long story short, I scored the sealing surfaces on the 1, 3, and 5 exhaust ports on the head. 1 and 3 cleaned up well with a file wrapped in 1000 grit wet sand paper. Number 5 is what I'm questioning. I gouged deep on that port inadvertently. I hit it with the 1000 grit sandpaper and got a lot of the marks out. I'm afraid to go any further as I don't want to remove too much and cause an uneven mating surface. I put a straight edge in it and its still flat. The gaskets from the manifold company are to volvo spec and are the coated steel type. They recommend dry install, but the company that sold me the parts also does installs and said to use a very thin coating of ultra copper rtv. Of course permitex told me the same thing. Man, I hate when I do something stupid and screw something up. Definately a learning experience I guess. What do you guys think? Advice?