[Motorola] Can TDN7407A 450-470 CELLWAVE Duplexer be Tuned for 440-450???

[Michael, W1RC]

I recently acquired a nice UHF Motorola GR300 mini-repeater and am 
considering setting it up on 440-450 MHz.  The duplexer label says it 
covers from 450-470 MHz and I am wondering if anyone with more 
experience than I with these units has had success tuning it down to 
work in the 440-450 MHz range?

TIA,

73,

Michael, W1RC