A year ago I bought an 650 Eddy AVS2 to put on my 440 in my Crown Coupe. Before I did that I tried it on my stock 440 Magnum in my Charger to see how it would work on it. What I noticed was that the idle was more smoother and basically drove nicer threw out the rpm scale. I also thought that it felt like it was a little down on power at full throttle compared to the factory Carter AVS. I want to emphasize...just a little.
Personally I would go with the 800 AVS2.