nothing wrong with "stock cylinder walls",..if thay in good shape! only way to know is to look at and mic them to see if thay still straight and round with no ware or gouges in them! if in good shape all you need is a good glaze busting and a good honing! thats for any piston or ring pack! now if ya got scored walls an ware in the bore it gonna need boring! only way to know is inspection and mic'in the cylinders!