Can I run 2 stereo amps in bridge mono?

In a word, no.

If you were able to invert the phase to one of the channels, then it would be possible. But the hookup you describe would lead to smoke, not just 'sparks' if you can pardon the expression.

@atmasphere To invert the phase I'd just have to plug left into right and vice versa right?

No. You would need a buffer that has no gain but inverts phase, plugged into one channel of each stereo amp you're trying to monostrap.
So you will need two such buffers, one for each speaker.
The signal for one channel then goes into a Y adapter; from there to one channel of the amp and also the buffer, the latter of which goes to the other channel of the stereo amp. Then the hot connections of the output are what are used to drive the speaker.

This is tricky and has to be done right, else the smoke is let out of the amp!
So that is the technique but the buffer itself is a bit tricky. I didn't find one on several Google searches.

@atmasphere  Thanks a lot for clearing that up! ;)