Once again, good luck with that. Hope the cast is true and everything lines up. Capturing the manifold in place using the studs you can see will give your seemingly necessary three arms a rest, before getting nuts on those obscured top studs. Holding the nuts in the socket with some butyl putty or similar might avoid them falling to places you can't reach.

__________________
Neil

2016 X5 3.0D
2009 X3 3.0D
2005 X5 3.0 Diesel Sport (sold)
2007 320i (sold)