Just to clarify:
* You are saying your Turbine outlet to the down pipe (exhaust) is okay?
* And the only problem is that your Compressor intake is not matching-up the CAC tube via an elbow?
* Can you attach pictures? Are you working with a rubber elbow or metal one?
* Physically I presume your old turbo matches your new turbo? But it's also very important that:
a) Has the same compressor billet wheel?
b) Has the same turbine wheel?
* Can you modify your intake elbow? ...probably not. ...So google "Holset ISM turbo elbow" and see what you get.
I found this company that maybe able to point you in the right direction:
a) What's the diameter of your old turbo intake and CAC Tube?
b) What's the diameter of your new turbo intake? ...And maybe your new turbo flange is designed to be used with a V-Band clamp and your old turbo uses a regular clamp and a rubber boot? (We need more information to help.)