Ever since I got my 55 over 15 years ago, I could never figure out what this bolt was welded onto the frame for. The car had been hot rodded years ago, I got it as a rolling shell, it had several sets of seat holes, shifter holes, various mounting tabs had been welded to the frame, etc. But this one just boggles my mind. Any ideas? (there's a similar glob of weld on the other frame rail, no bolt, and it's about 8 inches further back).