Exhaust manifold

[perra]

Hello!
I am planning to make an exhaust manifold for hx40 to fit my om603 engine and I have a few questions for you.
What flange is the hx40 you use, is it t4?
What size of tubing is the best to use?
And how is the best way to plumb the pipes together I have seen one that had cyl 1 2 3 connected to one port of the turbo flange and 4 5 6 to the other.
And I have seen one that had 135 to one and 246 to the other.
Which setup works best?
I tried posting in the english forum but got no reply there so I hope someone here is willing to help me.

//Peter