Well, from the more modern factory 5.0 I would have to say the Cobra/Cobra R. I don't know about Shelby or Saleens or what have you, but those aren't really "factory" models.
As for the Boss 302, the number I've found are........
290 HP
290 ft-lb
0-60 in 6.9 seconds
1/4 mile in 14.6...