estimated e.t.
Way too many variables to be precise...but,
490 "corrected" hp on a engine dyno wants me to think about 450, in the real world.....installed in the car. As far as weight, it's a little bit of a crap shoot not knowing all the particulars. So i'll just use a round figure of 3200 with you in it.
So with the above said, I can see low 11's @ the hi teens, as a possibility. Keep in mind, this is a rough guess at best, and a lot of things will have to be right, not just with the engine, but the car itself, suspension, tires, wheeling that 4spd, etc.
As far as taking on the Stang w/477 @ the rear tires.......likely not! Even carrying 3800lbs.
Good Luck! at least this should get the conversation started. :D