Two lines of thought.
1) If you offset the engine another inch or so to the left, a standard exhaust manifold clears the steering column, least it did for us.
2) I suggest you notch and box in the crossmember around the crank pulley, it makes the move to the left easier, and gives extra clearance to make it easier to remove and install the belt(s).

I think we has to do a bit of hammer clearance on the firewall to clear the right head, not much, but a little. Gene