His setup was a brand new "e-rod" LS3 package plus new 6L80.
Starting in 2007 the Escalade went to a 6.2L engine making 403hp.. mechanically it is most of a LS3 (same aluminum block and high-flow heads, less compression, less high-strung cam, MUCH larger intake manifold and arguably better truck accessory package). that is what I have in mine. 2007-2008 was called the L92, had Variable Valve Timing but no Displacement on Demand.. in 2009 they added flex fuel capability (L9H) then in 2010 added DoD (L94). All were mated to the 6L80 which is a GREAT option for these swaps. My swap with aluminum engine and 6L80 transmission (as big or bigger than my stock big-boy A442F) saved 100# over stock engine/trans.
My engine/transmission/ECM/harness/extras cost 5k from a junk yard with 120k. The engine probably didn't see the easiest/best life but it is running fine. Transmission did need rebuilding though.. I did that at home.
If you run bigger wheels putting larger brakes on a cruiser is pretty much the same as any other vehicle, with the one caveat being the rotors mount from the back of the hub face, not the front like most. This just means you have a shallower and smaller diameter "hat" and that means you are less likely to find an off-the-shelf rotor option that will work. I don't recall anyone offering a bolt-on big brake kit for our rigs, but I haven't been paying much attention. That said.. with 315s AND the ABS and LSPV deleted I feel my brakes work great, even with "just" OEM 80-series rotors/pads. It's not a sports car and I don't expect it to behave like one. But if I need to make an emergency stop it does well enough for me.