Using Adcom GFA-555s as monoblocks to power magnepan 3.3s in active biamp

Yeah, a long title but it says it all.  Presently I have my rebuilt Magnepan 3.3rs actively biamped through a Marchand active crossover, then using 2 stereo amps to power bass and mid/treble respectively.

I am considering taking two Adcom GFA-555s and bridging them and using one each to power the bass panels of the maggies. 

Since the Magnepans are 4 ohm rated, however it's only the bass panels I'd be powering, what are your thoughts on stability?

Appreciate the help.  Don't need suggestions on "selling all my amps and buying one bigger one" - I have a lot of different amp options but am a tinkerer and want to see if the power of a bridged adcom would be good to control the bass panels.