1Y block Turbo Return Line 5/8 Reduced too Much?

[mstephenson]

-Engine 1Y
-Turbo T3
-Return line empties into block

The "napkin" pic in post:
http://vwdiesel.net/forum/index.php/topic,36988.0.html
uncovered a leaking reducer 5/8 from turbo down to a 7/16? banjo bolt to block.

This post:
http://vwdiesel.net/forum/index.php/topic,40.msg220.html#msg220
says never reduce the line. It could create back pressure on the turbo and damage.

So, do I need to put a fitting in the drain pan? It is not a very deep pan and may have come off a 1.6. If I need to add a fitting, can I reuse the brand new oil I just put in?

Thanks
-m