Greg, I've been going through the same problem with mine, lately.
I ordered the Sanderson headers listed for this application.
You can see everything, with pictures here,
http://talk.classicparts.com/threads...headers.22242/
The thread rambles somewhat, with Lakeroadster and I discussing general things, but, it shows pictures of how I solved the problem.
It looks to me, my engine sits a little more rearward than yours.
I'm going with the F-body oil pan.
My engine is the 6.0 LQ9, so I opted for the 1,5/8" header tubes.
Steve.