I'm beginning to think that the problem has much more to do with gearing than carburetion. That 3.23 rear end is usually used behind an automatic transmission, where the torque converter effectively doubles engine torque during breakaway from a stop. That's why Powerglide-equipped cars used a 3.55 gear instead of the much lower ratio used for 3 speed cars. I once drove a 1963 AMC Rambler Classis with a 2.88 rear end, and it was quite a performer, even with a small 287 cubic inch V8, but only once if got rolling. From a stop, it was a lead sled!. Top end speed with that gear was outrageous! Combining a high gear ratio with an OD 5 speed is a sure recipe for performance problems.
Jerry
