Thank you.
I'm guessing that the W-2 headers follow the same pattern as the regular ones - 1 5/8"- 1 3/4" stepped versions.
I do use a shorter oil filter, something about 3.5", and most common headers, including TTI, will fit with the straight sump Moroso 8 qt pan. It's the Milodon 8 qt with the slightly shallower flared out sump that causes problems with some brands. But the TTI's fit those too. I can get my mini-starter in & out by some careful maneuvering of the starter with the steering cranked all the way over, to the right I believe. The stud extension is removed. There seem to be a couple of different size Mopar ministarters, but I don't recall which I have.