Here is my 94 D1 3.9 auto with original internals, injectors, ignition etc & abt 170K on the clock. Stock gearing with 245/75/16's.
Only power mods are a Mark Adams chip, performance exhaust (extractors and 2 1/2" single pipe) and a K&N filter (MAF regularly cleaned). Both dyno runs had these all in place. The second dyno run is following a proper tune (dizzy recalibrate), new plugs, injector and airways clean.
My numbers (inc peak power of 85Kw) seem compare very favourably to 4.6's. There has been a slight hesitation around 50 km uphill which I have put down to a a struggling original fuel pump and or regulator.
I am very happy with this engine and it is only when towing that I think about stroking in another litre and adding a torquey cam.

