i have just fitted 4 of the 6 throttle bodies off an e36 m3 onto the m44, i have now got it running but it is slightly rough. i haven't tried to drive it yet but have a feeling the injector flow rate is wrong so will try and see how i can fit a variable rate fuel pressure regulator which will hopefully sort it out.https://www.youtube.com/watch?v=UYGPAIDmZTQ
If your fuel pressure is correct and the various sensors working correctly the ECU should be able to cope with the minor increase in volumetric efficiency. Just get a good dyno tune-up.