Lot's of us have had trouble with the header/ Y pipe combos not clearing our 7 qt oil pans. Running into this problem on my the new motor going into my firebird I did a search and came up with a lot of complaints but not many solutions. So here's mine.
I cut a wedge out of the driver side collector and folded over so that it points straight down, maybe with a slight rearward bias, rather than in towards the center of the car and slightly forward like most of these units do. Then welded it back together. Then off the collector with a simple 90 bend straight back, around under the torque converter where I joined it with the Y that I had cut off there instead of letting it wrap around the forward end of the oil pan like it had before. I'll probably wrap it in header wrap to help keep heat out of everything, but fit is good, actually looks to be more clearance than the set up had in its original configuration with the stock oil pan which was tight in some places. I'll try and get some pics posted up for ya when I get a minute.

 

This is the most helpful post I've seen.

 

Can you post pictures?

 

+1 Please.
I can't quite see this in my head.