69 Dart 340 Swinger Street/Road Race build

Kind of like what I read, the factory welds are horrible which makes it difficult to get clean enough to weld over.............. Nice build, but if you ever weld up another k frame, have it hot tanked or chemically dunk tank cleaned before welding. It is the oil and road grime that is inside the k frame that percolates out when welding that messes with the new weld. I had my k frame cleaned by a shop that has a chemical strip tank big enough to take a car body. When I got it back it was clean outside and inside, welded fine.
I ended up using a carbide rotary file to grind down factory welds and then laying new beads down. And yes hot tanking the K frame prior to welding is the way to go.