some refer to it as a 54-57 trim upgrade. Some other shops refer to that when speaking of a t04 50trim compressor on a custom CT-26 format exhaust housing to allow it to bolt to the factory manifold. Either or, it's a hybrid. Peeps been doing it for years...not perfect, or even right depending on the dealer, but affordable.
thanks for the input. my turbo needs a new cartridge, and i was thinking about upgrading since it will only cost $100 more than just a stock rebuild.
i figure the extra flow will give me a little more to work with, and not a great cost if done now.