I have had as s363 on my 03 for some time now. The shaft seal was leaking a little bit so I rebuilt it and also decided to switch from my .88 undivided housing to a divided .91. I bought what I thought I needed on eBay. Rebuilt it and then realized the outlet on the new housing has a 4" flange and the old housing (which fit the stock exhaust elbow) is 4.25". I saw a lot of adapter flanges but which one do I need????

Thanks, Cooper

 

I beleieve what you are looking for is a Marmon flange.