Holleys will fit on the Mopar marine intake or the Stage 5, but I don't think you'll have much luck getting them to fit your stock intake, especially if you have a factory ram air setup. My bro had problems with the 1407 750's on his 517, so he switched to Eddy Thunder 650 AVS carbs & that made a huge difference in driveabiity, throttle responce & mileage, too (who cares about MPG with a Hemi).
As was also posted, go get an Eddy calibration kit ($65 from Summit)&
switch out your metering rods. Holley's on a Stage 5 intake are cool, but I think two 650's will make you happy. Tim Banning (FHO), told me he's getting over 800 hp on their big stroker Hemis with 650 Thunders.