im runnin a billet s480 t4 on the huron a/c kit with a 416, now youll be able to make a little more because you have less CI and can run more boost, but i made just over 900 on 18lbs and dont have but 2lbs or so left in it. so you should be able to make right around 1k wheel. and im auto witha 9inch. If i were you, id do my turbo, knowing i could make that power, and maybe run some spray if you want more. It almost sucks when you have a turbo that can make 1200 on your setup but thatll **** up your motor or lift a head, so for the street, if you want the fastest spool possible and 1k wheel.. a billet s480 should be the perfect turbo.
Idk why BW is out of question, but if i ran any other turbo, itd be a pt8047. that would also be a nasty turbo on your setup. if you were 5.3L id recomend a comp 78/79, the triple ball bearing is a nice option but you have a little to much motor for that in my opinion for 1k wheel
The comp 8087 is also a good turbo to look at.