Was driving my '51 yesterday and noticed a slight "knocking" noise as I headed for home. I had driven for about 45 minutes before the clatter began. Started it up this morning and got LOTS of noise! Used the old broom handle noise test and determined that it is from the lower part of the engine. This is an original 216ci, babbit type power plant. What to do? Drop the pan and try to shim the bad connecting rod? Neighbor (old mechanic) says the crank is most likely scored and will need work. With bad crank, shims won't last long. If I drop the pan, what are the "Tell Tale" signs that I should look for? BW