On the dyno a good 1050 or maybe 1150 Dominator will pick up 15 to 20 hp if you use a good Dominator intake. Using a Dominator with an adapter is a crap shoot. It usually doesn't work very well but sometimes it works okay. At 750 hp you are probably better off with a really good 4150 carb on your existing intake. The best 4150 I've ever run on an engine like that was a QF 1050AN. I used one of them when dyno testing my 470 combinations.