Magnum was a name to imply maximum power. Later, Magnum small blocks were actually modified block and head castings for smog reduction and added pwoer. Magnum small blocks have no mechanical fuel pump and have reverse flow cooling with a modified timing cover and different water pump housing. Magnum heads have rocker stands instead of rocker arm shafts, with oiling through the pushrods.
Yeah, essentially the term has had three uses. The first use was essentially a marketing term for the powerful version of the sports-oriented cars. The second was the '78 Dodge Magnum vehicle and reuse in '05 for the LX waon, The third use was the name applied to the revised LA engines '92/'93 era, likely in homage to the increased power and performance out of those engines compared to their LA counterparts.
Absolutely. It was the performance name used of old. It oringinally meant performance exhaust manifolds, larger cam, higher compression, definitely four barrel carb or six pack carbs, HP2P block for big blocks, these sort of things.