hey flynbyu, the vq harness (of the fx at least) has one plug that is the main bulkhead plug to the ecu, it then has a secondary plug that plugs into the dash harness... the dash harness contains the seconday plug for the ecu, so on the fx engine harness it does not contain both plugs to the ecu, same as the HR harness I got from the g35x... what car was your vq swap from? automatic or stick? awd? I don't know how other vq harnesses are done but as far as the fx goes, there is a secondary ecu plug from the dash harness for sure...
I winded up picking up an r32 5 speed awd tranny and an r34 getrag 6 speed awd tranny too... going to probably have to cut off the bell housing & graft a 350z 6mt bell housing to the gt r tranny I think... now to convert to stick I'll probably have 2 options, either keep the auto tcu in the circuit with dummy loads & simulated in/outs or switch out to a 350z 6mt rom, but that will complicate the awd I think, there is no HR with 6mt that is also awd... worse case may be to use a 6mt rom & then use a stand alone center diff controller... just adds to the fun
I also picked up a g37x motor, hopefully I can use the 3.7l block with the 3.5l heads eventually... I have no plans on trying to run the 3.7l vvl heads, that would require yet another whole harness & ecu swap again...
to run one of these engines in another car I don't think is so hard, it becomes hard when the other car is also an obdII car that has several other computers that you need to play nicely together, but if your just looking to run the engine stand alone with no can buss integration then it does get a bit easier...