5.7 0r 6.1 with msd hemi 6 and carb

I think as far as carb vs EFI on the new Hemi that the problem really lies in the manifold, not the fuel distribution method (as seen on the graphs). Theoretically speaking both can make the same power, granted EFI can make more power more often because it can adjust to environmental changes, but there hasn't really been much for development on carb intakes. The huge high rise drag pack setup might help to even the playing field, but you're not going to fit that under a stock hood without setting the engine on the ground, lol.

As far as cruise timing I think the stock MSD setting is around 42-45 degrees, which I know I've run at without issue. 50 does seem a little on the high side. You can always set it low and just slowly creep up the setting to see how it responds. You really don't need tons of cruise timing unless you're really trying to lean it out for gas mileage.