Last weekend I picked up a used stock Y-pipe with an SPD Y already welded in. I have the old Y out and the new one is ready to go in (napa didn't have the gasket between the Y and the cat but it will be here tomorrow). I had to use a sawzall to cut the top bolt off where it meets the cat, and one below that broke off but I will be replacing with new hardware.

I paid $80 for the part and am excited to feel the difference!!

 

I doubt you will objectively feel the difference. I would do it again anyway.