Are you runnin the 3 12" jbls?
Ok, that's out in left field. Why would you say that?
They should hold up... You're not runnin much more than their recommend rms
well straight blowin them isn't the way to go... You might want to try and break them in for awhile and then go to increasing power. As far as ported goes, I'm pretty positive it will be louder.
You should be alright, you didnt smell anything burning did ya? Just keep it low-medium vol for like a week- 2 weeks to allow all the parts to break in... Sealed boxes tend to have high excursion for the subs and I'm pretty sure that isn't good for them right out of the box compared to a ported enclosure where it doesn't take as much excursion to get loud at the hz the box is tuned at