[dstjohn99]

You should have only clean metal on the heads and block before installing new gaskets. I have different scrapers depending on the material and situation.

My favorite is a 6" length of an old file with a nice wooden handle. I cut it short and sharpened the end - though not too sharp as I do not want to scratch or gouge what I am scraping.

My next go-to is a piece of acrylic, like plexiglass, about 1/4" thick. I can sharpen this very sharp without fear of scratching aluminum or soft materials. It does need sharpening often but its a quick touch on a disc sander and back to work.

I also have a small curved steel scraper and a razor blade scraper. Used with extreme caution any of these can be used without damaging the block or heads, but with aluminum I mostly use the acrylic scraper. I have even used a wood chisel, but only with extreme caution.

Last I will take a good quality bench stone and some WD 40 and stone to remove any high spots or dirt areas remaining. No need to worry about rust areas inside the water jacket or on the surfaces that are not for sealing.