[Repeater-Builder] DB 4072 Duplexer, Knowledge, will they tune the 440 Mhz Ham Band?

[n9lv]

I have a fellow ham who has a set of DB 4072 duplexers, wants to use 
them on a 440 repeater at about 30 watts output.  Has anyone any 
expierience tuning these duplexers, and how well if they will, work.  
They are currently set on 463 Mhz, and are designed for 450-470 Mhz.

Thanks.

Mathew