I have a k03-029 borg warner turbo in my car and after a lot of miles I think its time for a service (due to the fact that I sometimes see a little white smoke from the exhaust which dissapears however after a quick pull)

Now, although I have searched and found in many forums that the k04-015 is a direct bolt on swap for my turbo I havent found or seen anywhere if its possible to fit a k04-015 cartridge to the k03-029. By doing so, I am hoping to see no change in lag, increase performance by the bigger chra (ok I will need a tune) and service the otherwise bad turbo.

Any thoughts? Has anyone done this? Does that particular k03 turbo need any work done to it to accept that bigger cartridge?

Thank you in advance