Ok, so I saw Kilmer tossed up some info, but I’ll toss in my .02.
So, you’re k03s w/X+ is holding probably a max of around 14psi @ redline? As Fah-Quad mentioned, it’s not about boost pressure, but about the actual volume a turbo flows - but that’s not really as important to discuss until you know what you want to do with your car.
Also, I’d very much so like to see a dyno w/a k04 265whp and 303wtq. My k04-020, which is the biggest k04 you can get w/o getting some sort of a hybrid made 240whp and 280wtq. Probably pushing 250whp and about the same wtq now, but still I doubt you had that as it needs a new mani, injectors, etc etc etc. If you’d like I’ll take you for a ride in my car. Heck, if you’d like I’ll sell you my setup :).
Also, for what it’s worth, the 210/274 couldn’t have been correct by any stretch as far as I can guess. Maybe that was uncorrected and it was freezing cold out or something. Or a bad RPM pick up could be where the crazy tq numbers are coming from. I could see that out of a k04-001 on a stretch, but never out of a k03s.
There is 1 turbo that you can 100% bolt on to the manifold you have now and use the oil + coolant lines you have now + turbo inlet pipe you have now. It’s the k04-001. This will hold probably… 16-17psi @ redline. That would be your only direct bolt-on turbo. That turbo would probably yield 20whp gains. After that, everything SHOULD be put on a new manifold and will absolutely need new lines. The ATP eliminator kits that bolt up to the “stock” manifold are OK solutions, but honestly they are not really that great on a stock manifold and don’t really use the best hardware out there. And you’re still going to run probably $2500+ for their kits and you can get better products for the same money.
Also, I’m not sure if you know or not, but the stock rods are good for about 300-320whp depending on your car/tune. The better the tune the harder you can push them, but really your best bet it to replace them right @ 300whp. The pistons are forged though and can handle more, so you can get away with doing ONLY rods. You’d probably be looking at $600-700 in parts alone for those if you did the labor.
As for your GIAC, they offer files for plenty of big turbos. You’ll just have to pay the difference from X+ to whatever you got. Usually $200-300 for the upgraded file.
Honestly, I’m not trying to be a dick, so don’t take it as that, but you can ask more questions if you’d like. But you’re missing a lot of factors from what I read. Kilmer knows a ton about VWs and I know a pretty good bit. I also think Fah-Quad is pretty knowledgeable and in general you can ask most anyone on here about turbos and get some info regarding psi vs. cfm or whatever it is you’d want.
Also, FWIW, with my 6spd (typically slower by up to .3 and traps are slower by up to 3 mph) when I made 200whp and 232wtq @ Hybrid, I pulled a 14.4 @ 98.xx @ PRP w/a 2.27 60’. Now with my k04 setup my car should pull mid 13s @ around 103 probably. TBD currently.