Rated spec is 20 MHz for that radio but we all know they will lock above and below that but to what extent is kinda radio dependent. You're looking for about a 26 MHz spread and that seems reasonable.
The VCO can be adjusted fairly easy with a volt meter. You just program your highest and lowest frequencies, monitor the VCO steering line voltage, check high and low (both TX and RX) and see if the voltage stays within specs. There are tweekers for both TX and RX to achieve this. And yes, if you lower your VCO's range, you will lose the top freqs, the VCO can swing only so far.
Now for performance. The TX might do alright down at 442 (with a slight reduction of power), but check the RX down there and see if seems deaf. If so, the preselector will need to be aligned to your new freq spread and this will require some test equipment.
