Rasberry Pi  Raspbian OS

So this relates to the Moonlanders,  but is more of a Raspbian question

When I reboot my pi,  it reassigns all USBs   ttyUSB0 becomes 2,   4 becomes 8.....etc....

I am using 4 v1.2 Mooonlanders and 8 v2.0 Moonlanders,  so I need to specify the USB in order to get them to work with the correct bfgminer.

Any idea on how I can lock them down to their # even after reboot?

This problem may or may not continue once jstefanop enables the new bfgminer to run both,  but I'm guessing I'll still need to identify by ttyUSB#