My 6cyl. engine (1972 250C) has a slight erosion at top of cyl liner between #1 and #2 cylinder which allows leak between cylinders. I have driven the car in a tractor putt-putt mode for several thousand miles since head rebuild with mostly only an issue at idle. My question is about the cylinder liners, whether they ar cast iron or steel, with the expectation that I might deposit via MIG or TIG welding, sufficient metal to allow a tight seal against head gasket. The welding would be placed bit by bit to prevent heat warp/build up and the finish would be by hand; all with engine in car. Except for telling me its all a wrong idea, any input is appreciated!