See my post here about gains with a 4150 to Dom conversion...
Go with the Dominator...
http://www.offshoreonly.com/forums/n...y-results.html

The old school rule is 2 cfm, for every 1 ci. Example 500 ci motor you need 1000 cfm carb, or 1050.

You can make that power with an 950CFM 4150 flange carb and be a little more fuel efficient and have better mid range.

Most guys go with Dominators, and they are acceptible, but they are overkill for that amount of HP. I have done done both carbs on the dyno and switched intakes and the top end numbers are the same. The fuel usage is a little less on the 4150 carb and the mid range numbers pick up faster.

Either way the carbs and the intakes are about the same price. Flame arrestor may be a little more expensive with the Dom.