My brothers dead stock 33GTR ran 13.2. he has since removed the boost restrictor (boost up from 12-14psi) and got an extra 22 or so AWKW.
I would still consider it stock and I think it would get close to breaking into the 12's. if you have a good clutch, tyres, launch at 7G+ and have a good fresh motor it is possible to get these sort of times.