Demon carbs, when drilled right and not full of shavings, run awesome.

Having said that, I am proud to have a Holley 750dp on my car after my own problems with BG carbs causing it to break engine parts.

Just know that Demon carbs are underrated about 70-80 cfm. So a 650 mighty demon will actually flow about 720 which in my opinion should run amazingly on your car