on alot of the websites for 6.2l and 6.5l upgrades, some of the upgrades can only be done on the 6.5l. for instance i found an oil cooler on dsg website and they say it will only work on a 6.5l. Can upgrades for a 6.5l be done also on a 6.2l?

Early 6.2\6.5's have 1/2" oil cooler pipes - late versions use 5/8" pipes, so that 'cooler won't directly interchange.

Requires the late pipes and the fittings for the block.

Other than that, late and EFI cranks differ incl one-piece rear oil seal, late heads get different injector angles to clear the turbo exh manifold - requires appropriate injector pipes.

Most else is interchangeable, long as you use the appropriate head-gaskets and pistons.

Most upgrades are for the turbocharged engine - not much out there for the n\a version, so you're basically limited to freeing up the intake path and the exhaust path, which helps the n\a engine a bunch.

Is one reground camshaft specifically for the n\a motors, gives a little more lift and timing but needs extended pushrods, as the lift is implemented by reducing the base-diameter of the lobes.

The standard DSG gearset fits, and will stabilize timing such that IP rotation is no longer required to compensate for deteriorating chainset.

Later injector pipes are larger inside diameter, allowing more volume, probably not necesary for the n\a engine.

All the serpentine belt stuff fits, allowing for the '97 HO waterpump and cooling system upgrades - again, probably not necessary for the n\a motor, but the serp belt is a nice upgrade.

So - your basic intake\exhaust improvements, maybe an upgrade to a 6.5 engine, etc....................