Most of these cars had KKK from the factory, but in many cases when the trap-ox recall was done, it had a replacement turbo which in many cases was the Garrett T-30 with the 50 trim wheel.
A bigger turbo will help if you turn up your fuel a little. Sixto and I had reasonable improvements from the T-30 55 with IP adjustments, but much added boost will require an intercooler. Lots of our saga here:
http://www.peachparts.com/shopforum/diesel-performance-tuning/290694-om603-semi-super-pump-testing-fitted-bosch-6-0mm-elements.html I made my modifications with the 3.5L pump because of the higher fuel at low RPMS and higher injection rate cam. Both of us used the factory air filter system (sans airflow meter), factory exhaust, and factory injector nozzles which all have adequate capacity.