@
justcozz
I don't know too much about Stainless Works, but I believe they have two connection options. One is performance connect and the other is factory connect. The latter is meant for a bolt-together flange connection. Yours appears to be setup for a slip fit clamped or welded connection. You likely need to either get a flange added or cut off the flange portion of the exhaust and get everything welded or clamped together.
Are you installing the headers and y-pipe or just a new y-pipe? Only asking because the headers weren't in the pic. Also, I believe the headers are a pretty intensive install due to space constraints etc. If you're already hung up on the y-pipe to exhaust connection then you may want to evaluate doing all of this yourself before you get in over your head. Not a criticism. Just some advice. I installed my own exhaust, but I sure wouldn't want to attempt a header install. Takes most shops around 8hrs I think.