I highly recomend a Dyno Tune. You will find it not really making mush boost until 1900 or so and you really are babying it. They Hate 2000rpm, Hate it. 2000rmp is the magic number for a Kettle in my opinion for both my TDs. Cruising ar 2200 to 2400rpm and they just sing. cruisoing at 2000rpm and the EGTs can get a little Hows ya father.
Once Tuned you could make 4000rpm and the only thing stopping you is your mechanical sympathy. a stock TD42T will be pretty flat through the 3000rpm onwoulds but tuned and there is a power curve up there that they just love.
Fit it up with a decent Turbo and 12mm pump and nice intercooler (The factory is junk) and it will be transformed. Night and Day mate.