What a mess. I'm replacing all seals in my Saginaw 4 speed but one has been hard trying to find. Its the speedometer gear seal. This is the tiny metal/rubber one that goes in the middle for the plastic gear. My local Oreilleys could not find it. The kid actually showed me a pic and asked if that was it. He showed me a speed sensor that was electric??????? I told him 1978. I went to NAPA and they ordered it. I just got back from picking it up and its way to small. I guess I need to go to a transmission shop. I bought a seal kit but this one and the front shaft cover seal was not included. Go figure