HOw are the Generation VI (6) 454 Blocks compared to the older 4 and 5 blocks? are they more expensive to build.  How much would a standard Bore block with the caps be worth?  

There is very few differences. Not being able to use a mechanical fuel pump or block-mounted clutch linkage is the most notable. Mk IV heads will work.

The demand for them isn't high as they aren't rare, it will probably be worth about the same as any other good big block 454 core.  

It has the provisions for a fuel pump and the boss tapped for clutch linkage?  

96 up are also hydraulic roller blocks,also there's a head gasket designed for putting on IV heads on a VI block.     WIEDER  

Sorry, I confused the Gen V and the Gen VI...  

Yeah, the heads from a Mark IV won't bolt onto a Gen V without some mods.

The big problem with the really late Mark IV and the Gen V blocks was core shift. The tooling the blocks were cast on was pretty worn out in the 90s, since they'd been cranking blocks out since the 60s. GMPP is coming out with a new block that'll accept any parts from Mark IV or Gen V with not modifications.  

I think I have the block you say is coming out according to thie :
Gen 6:  GM recognized that it did not make any friends when it designed the Gen 5, and so they chose to revise the coolant passages again when designing the Gen 6, allowing the older heads to be used without coolant seepage problems. The boss for the clutch bracket returned, but was generally not drilled and tapped.  The non-adjustable valvetrain remained, as did the one-piece rear main seal.  Some but not all Gen 6 454 (and not 502) blocks regained a mechanical fuel pump provision.  Production engines installed in pickup trucks got a high-efficiency cylinder head, still canted-valve, but with a modern heart-shaped combustion chamber of about 100cc.  The intake port has a "ski jump" cast into it to promote swirling of the intake air flow.  All production vehicles with a Gen 6 used a 454 version, but over-the-counter 502s are available.  The Gen 6 is sometimes referred to as the "Gen Fix" because it fixed a number of issues that disappointed enthusiasts when the Gen 5 was released.  As an added bonus, most if not all Gen 6 engines use hydraulic roller lifters.  

I have a '99 gen VI 454, inside the block it says "7.4/8.2" between cam bearing journals...my question, could this 454 be bored to a 502?  

Unless the cylinders are siamesed (material cast between the cylinder bores), the block cannot be bored to 4.470