Hello Colin,
There is a specialist section within the Chevrolet "Stove Bolt" forum dedicated to
The Engine Shop. They might be a good source to answer your question about changing the sump and oil pickup arrangements.
https://www.stovebolt.com/ubbthreads...gine-shop.html
There is currently 1,487 pages just for the Engine Shop so someone should know the information about the 216 engine that you need.
Kind regards
Lionel