Changing the oil pan in the car (73 Charger 440), when I removed the pickup tube I noted that the end of the threaded hole in the block is quite rough. Some of the final threads are broken and uneven. After cleaning it out and checking the pickup tube threads, I am having a bear of a time getting it started. It's beating up the pickup threads and more fragments of threads in the block keep breaking off. I am on the verge of getting royally ...... well, you know.... on this simple project! Does anyone know where to get a thread chaser for the oil pickup hole in the block?