Default is posible to change/flash other base band radio

As my question, is it possible to change the baseband or/and radio on the xt862 rom by the radio of the xt883 rom ?

I try to implement the radio img in the xt862 rom, the flash is correctly, but when the phone boot, there is not signal.

I have somme probleme on the xt862 rom about the bdm and the mms (don't sent), and on the xt883 i haven't this problem but other problem (with sync, and some application).

Thanks for share....