carb recommendations

I see no problem with a mechanical secondary carb with your combo, stall, gear, etc. A 750/770 would be the logical choice, since I have to think performance is really in your mind with that setup. Nothing wrong with a 650/670 at all, but you'll probably leave a few ponies on the table at the big end. Either will be fine and streetable as long as their tuned in for your car.

I haven't personally used a "Ultra".....after my time, lol. But I do prefer the Holley over the Demon.



P.S. I should clarify, the 670/770 numbers were in relation to the Vac. Secd. Holley Street Avenger carbs that are available, incase you decided to go that route.