FM and AM xtals interchangeable. Duh.
 

Troubleshooting my LS10 I tried this and it worked. I had a 75.930 AM TX XTAL and a FM 75.930 RX XTAL, and intuition told me they would work together, and they did. Think about it: It's the same frequency the just used different means to get there. I.E.: frequency modulation versus amplitude modulation. Good day.

how is your range mixing the two frequencies?

As far as I drove it, didn't officially test it.