FWIW found an input gear on ebay from a 2003 NP231 that is said to mate with NP3550.... aka- likely exactly what is in my 231 already. Will try that to see it will fit in the 242. If so..... most the way there. Hopefully matches the bearing size and gear matting needs. Doing it this way leaves me a 231 to sell with a newly installed SYE.