Without a 3.73, or maybe even 3.91's, I don't think a BONE STOCK NA car is ever going to break into the 13's.
No two cars ever perform exactly alike, no two drivers do either.
But for one car to run nearly a half a sec. faster than the norm, I'd suspect that it was "broke in" pretty hard, and the engine is probably "loose" compared to one that wasn't.
Just my $0.02.