AutoCAD Inventor :: Drawing Multiple Angled Holes In Block

I need to create a adaptor to go from one 96 hole array pattern to a smaller 96 hole array pattern.  The pattern gets smaller in both X and Y.  This would go from vertical hole to angled hole back to vertical hole.  One or both of the vertical sections could be removable to allow this to be a drilled part.  The center section would be a solid block. 

Since each hole will be at a different angle (in two different planes) it seems like I would need to create a separate plane for each hole and extrude from that plane.  In addition to being error prone, this would take a large amount of time.  Is there an easier way? 

It would be straightforward to create a block with points for the large 96 hole array on top and the small 96 hole array on the bottom.  Is there some kind of point to point method of creating a hole at an angle?  A construction line could be drawn point to point but is there a way to make a hole from that?