Busted Knuckles

What is it about LS engines that lets 'em swallow big cams and idle close to stock? I've read of several combos with cams in the 240 @ .050 range with no driveability issues. If that were an old style smallblock, or even a big block for that matter, it would have a rough enough idle that it wouldn't be much fun to drive. I know that big-inch big blocks like a lot of cam but we're talking engines in the 400 cube range. I'm trying to decide on a cam for the 402/L92/L76 combo in a 3200 lbs manual tranny C3 that'll be used for a good bit of cruising and twisty mountain road driving.