Exhaust y-pipe question, please help

[run2cars]

Looking for an o/r y-pipe to fit stock headers, 2000 ecsb 5.3 z71, anyone make them? Exhaust is stock right now, looking to install the y-pipe with a catback, ive serched and cant find one other than peope cutting there stock one. any help apperciated.

[1988 GMC 355]

Best bet would be to have one made.

[SUBURBIAN]

What do these "stock headers" look like? I'd love to see them. They must be dealer-installed or something.