Now go wash your mouth out with soap !!! 
The LS series of engines refers to Gen 111 and Gen IV engines. LS1 through to something like LS7 or some crap now. Correct, there are iron and alloy block versions from about 5L through to 7L. But that's beside the point as they are just std crappy GM small blocks.
Soooo...... about 6 or 7 years ago, GM release the new Bowtie Block, named LSX. It's a cast iron, siamesed bore, 6 bolt/cylinder configuration, (std LS are 4. Even Gen I and II small blocks were 5. WTF were they thinking
) forged doweled mains, genuine priority mains oiling and the best part, they can be drilled out to 4.2" bore size capable of 500 cubes and still hold up to 40 psi from a kick arse pair of spinning carburettors.
(OK, they don't hold it for long. A lot of **** breaks)
GM then decided to slap some together and sell them as Bowtie crate engines, using the LSX block. They were/are waaaay over priced pieces of snot only capable of around 900 or so HP.
With the said mentioned kick arse spinning carburettors, a touch over 2000hp is achievable with an LSX block filled with aftermarket goodies. Or so I'm told 
Shane.
(What was this thread actually about
)
Thanks Shane, I'll stand corrected. I was of the opinion the LS'X' was all of them.
And this thread was about finding a 4WD home for them