As bedlamite said, LS is GM's current engine series. In Ye Olden Days, GM eventually pared engines down to essentially two basic architectures... small block and big block. Revisions were limited mostly to head design. In the 90's GM recognized that the 50 year old architecture had been pretty much tapped out in terms of potential and were self-limiting in terms of any significant improvements. As a result, they did a clean-sheet engine design. Thus, the LS ... a simple single-cam OHV design with a metric buttload of power potential and few if any of the old engines' inherent limitations.
One of their biggest attractions is a huge aftermarket following and the fact that they make stupid good power without a ton of work. You can yank a garden-variety truck 6.0 out of the junkyard and easily make 500 reliable HP by simply swapping the cam, bolting on a good set of headers, and replacing the fuel injection setup with a carb. Their design also revs to the moon without issue. 6500 rpm is no sweat for a stock rotating assembly and there are plenty of relatively inexpensive crank kits that will stand 8000+ RPM. Since HP is a direct function of RPM, this is a giant "PICK ME!" sign for gearheads. Build something that makes decent torque, spin the crap out of it, and there you go. It doesn't hurt that the LS responds very, very well to forced induction.
However...
As much as I like the power potential of forced induction, pressure equals system complexity and mechanical stress. For a given power level, I much prefer making it with displacement. Lower the stress and you have more headroom in terms of reliability and durability, plus more displacement usually means a much broader (read: much more usable) power band with better low-rpm characteristics. That isn't so much a thing with variable cam timing and electronic controls, but for a simple hot rod application it really does make a difference.
This beast has to be a ground-up new design based on the big block, but with goofy-tall deck heights, significantly elevated cam centerline, and super-thin cylinder liners or some type of expanded bore spacing. There just isn't enough room in a stock block to poke and stroke that far. At 79 cu inches per cylinder, the pistons must be the size of coffee cans.
Brad