I think you just need a hardware kit for the K04's to bolt right on but no other modifications are needed to the block.
Once the K04's are in you could drive ok with the stock/chipped engine management but to see the maximum horse power you would want to get larger injectors and programming to support it all which will give you major gains. I wouldn't know the HP exactly off hand, but depending on the tuning/injector sizes, and other supporting mods you would probably see around 400HP at the crank.

 

In that same vein...

I've read numerous times that the only way to replace the turbos on an A6 is to pull the engine. Then I've read a few times it can be done without pulling the engine by removing, well, just about everything else. Could someone comment on which case is true? The reason I ask is that my 01' is about 85k now, and I realize that the turbo issue will come around sometime. I can't pull the engine, but anything short of that I have the space, ability, and tools to do. But is it even possible? From having done the timing belt (and related), it's awful tight in there, but.....

Anyone DIY?

 

I would imagine it would be just as hard to pull the tranny and try to sneek them out of there than it would be to just pull out the whole sha bang. So either way its gonna suck un-less you wanna hack up your car with a plasma cutter to get them out.

 

Joeski mentioned somewhere above that it was possible to do provided you dropped the transmission. I'd assume that doesn't involve cutting anything Joeski....care to elaborate? Anyone care to elaborate?

Though, how on earth would one get the transmission out without taking the engine out? I know on my old Volvo 240 you could get away with that by taking off the tailshaft and unbolting the bell housing, but I somehow don't think it's that easy with an A6.

 

You can pull the tranny out on any audi without pulling out the engine, it has a 16 hour labor time but it can be done. Not easilly like i stated before un-less you have a damn good hoist.