If it were me, I'd go with the 470cfm Truck Avenger.

I've wheeled with several people using Edelbrock performers and they just don't do well off road.

I ran a Truck Avenger on my old 85 Grand Wagoneer and it was just about as smooth as fuel injection at any angle I could put it. Sure, it was a bit temperamental but for off road, I wouldn't go with any other carburetor.