Like rumbleness said, it's all about the lifter diameter. In other words, the larger the lifter diameter, the more lift per a given duration that lifter can stand. Make sense? Sometimes though there are situations where you actually WANT a Chevy or a Ford lobe on a Mopar camshaft. It's all dependent on what you're doing. Say for instance you're running a large by huge solid roller on the street and you want it to last, rather than wear out the valve springs or the rest of the valve train. In that instance, you're not lookin for every ounce of power. It's probably gonna make a pile anyway, so if you're not racin for money, you want that expensive stuff to last a while, so you choose a lobe that's less aggressive "to a Mopar". Conversely, you may want something that's on the ragged edge of everything in the world and if that's the case, you're probably racing for dough and want to spank everything out there, so you choose the lobe best designed to the Mopar lifter diameter to do that. Chevy especially does not have that advantage, because they cannot stand a Mopar lobe with a ton of lift without ill effects. Mopar has the best of both worlds, because we can pick and choose lobes from any domestic lifter diameter we want to accomplish a given objective. Did any of that make sense?
