Uplift 9.05 to 10.1: Lead Times Blew Up?

We are conducting trials of auto-converting 9.05 to 10.1.600, and are at the point where we are trying to get MRP to run. We started with a Mfg Lead Time Calculation, and it appears something went wrong with the calculation of lead times. The first part we’re looking at is a manufactured item with many layers which went from 4 days to 505 days. Of course we are drilling-down the BOM to see where the numbers are similar vs. different, but I wanted to post here: has anyone had this happen and can offer any ideas?