I just bought a 1955 210, I have been trying to get the speedometer to work right. I replaced the cable to get it to stop jumping around and now it is about 10-20 MPH off. I am guessing the rear axel is not orginal and I am trying to figure out what the ratio is. Is there a trick to figuring out the gear ratio with out taking the rear end apart? I have already looked all over the axel for some sort of tag or mark saying what the ratio is. Thanks!