I may stand corrected, but I am almost positive that I have read here that the injectors of N/A are not compatible with a Turbo. I believe there is a big difference in pop pressures.

For the difference in idle smoothness, try adjusting/replacing the rack dampener bolt on the rear of the IP. I think there are photos here somewhere if you are unsure of where it is.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )