Possible use ASTRO Spectra building P25 digital repeater?

[bh7juo]

I found some DIYers use 2 ASTRO Spectra radios to build a P25 mode repeater system.It seems like to radios link with audio and control line,and it has not good transmit effect.
Because ASTRO Spectra has DSP,ADC DACchannel build-in,I consider that if we can find RX radio (for example)FSK modem output data and line clock,connect them to TX radio FSK modem data in and clock in,so 2 radios connect by digital line(s),transmitting using digital directly,then it will become a really digital P25 repeater,and may have more exciting features.....If there are some different between TX and RX digital line(such as data format),I will use some devices to change that(CPLD,MCU,etc...)with program.
So whether it's possible to bulid as that?How to make it?