17748 comes with the -23 degree in block93.
This is the offset in degree between crank and intake cam and should be zero.
Have you used the intake cam from the old head in the aeb head? Check the "thing" on the intake cam in the G40 sensor. Dont know the english word. Maybe they are different between M5.9 and ME7.
Is the engine running without strange noise?
Check the timing belt.
Check the position between both cams. (16 chain links)
A non activated vvt tensioner with correct oil pressure is the same than a "non vvt" tensioner.
here is the "thing", what is it called?
http://funksoulkitty.org/shockypage/8engineswap/med2cpstw3.jpg