FMX FE bellhousing

Hi, I have a 1970 LTD with a 351W and FTX. I'm switching out a 390FE and trying to keep the FMX (I don't trust myself modifying the driveshaft and crossmember to put in a C6. Does anyone know where I can get an FE bellhousing for the FMX to fit the 390 or exactly what I need to do to modify the driveshaft and crossmember for the C6?

Thanks a lot,
Michael