Disclaimer: The following was done with full understanding of the risks and knowingly voided my warranty.
I ran the 12k at .5 bridged for about 6 months before I decided I wanted more power and went to 2 7.5ks. Took it like a champ. This was backed by 2 singer 400A alternators and 8 XS D1400s as well. Voltage never dropped below 14.8v.
So here is the real question, are you willing to pay a $500 repair bill if you blow it? If so, I say go for it.