non turbo upgrade kit for OM617?

Hi everyone,
I have a 300 gd from '82 the engine is OM 617, next summer I'm planning to "rebuilt" my engine, I thought wile the motor is dismantled its the perfect moment to "upgrade" the motor as well, I'm aware of the turbo engine end the existing of some turbo kit too, but I don't want a turbo, its my belief that a turbo engine of this generation only produce more power and torque @ +/- 2250 O/MIN, end in the lower (- 2250 O/MIN.) even has les torque, I believe also that the legendary "long live" of the OM 617 is shorten by adding a turbo, no, I rather keep my engine non turbo, nevertheless I'm looking for some extra momentum in the lower O/MIN., I no, making the air com in easily end have more fuel injected + improve the exhaust is gone give me a little improvement. but that's abate all, I wood like the no more abate the injection timing, the injection presser, enz.... can a alter this for more power? how? what else can a do to obtain more power?(+ 20% wood by greet) do someone no a site related to this subject? do someone now of a non turbo upgrade kit for the OM 617? while the engine is worldwide in use (boots, mobile compressors, generators enz....) I cant believe nobody have try this before me.
have been looking on the internet, noting so far, hoop someone can help me
thanks in advantages, whish you all the best,(end lets hope 2004 will be a great g year), Oswald