Removed the diff centre from Lynnes 57 Thunderbird last weekend to track down a clunking noise .Found the problem of  a missing tooth on a sun gear .I thought that Automatic Thunderbirds had a diff ratio of around 3.1 or 3.2 ??? This one has a 3.7 ???? No wonder it is quick on the take offs ???? Case has WAA 4025- A  cast on it .. Tried to decode ,but can't find a prefix of WAA ???Any ideas ?

yblocksdownunder