First off, unless there is a huge crack or something, anything can be fixed. Block can be bored out to the maximum SAFE spec, and oversize pistons, or can be sleeved back to stock specs. Valve guides can be bored to fit oversize valve stems, or bronze inserts can be fitted and honed to stock valve stem specs. The problem is finding a shop that can be trusted to do that kind of work. The corner garage is NOT up to that task. My guy does racing engines, marine engines, truck engines, anything that is internal combustion he can and will work on. I know finding a guy like that can be tough but it is the only way to go.