Try a Holley Truck Avenger. They come in 370, 670, and 770 cfm models.. The Truck Avenger is basically a square bore 4150 4-bbl that's been modified for off-road use. You can get it with either a manual choke or an electric choke - mine's the latter. It's rated for 40 deg nose up, 30 deg nose down, and 30 deg side tilt. I have one on my 360 and a buddy has one on his 304 and they work good. Not cheap, but neither are Edelbrocks. Mine was about $400. I've got it on an Edelbrock Performer intake manifold.
1977 CJ7, AMC360 V8 w/ headers, DUI HEI, Edelbrock intake, Holley 4150 carb, , TF999, D300, D30 front and AMC20 rear with 4.56 gears and lockers both ends, 4" susp lift, 2.5" body lift, 35" BFGs, ARG steering, 8000-lb winch, etc.