[FattyBoomBatty]

If you can get all the old gasket stuff off the block without sandpaper or razor blades or what have you, then do that. You could even maybe use adhesive remover soaked into a rag/towel to loosen up left over gasket stuff, that last part was a guess, I've never done it before, but hey, might work. I have used a razor though, and you just have to be careful.