Exhaust Donut Question

[carlsbadGN]

I recently had a turbo elbow ported professionally. Today, I noticed that the metal ring that fits on the inside of the exhaust donut can now pass through the elbow exhaust opening since material that provided a tight fit was removed in the porting process. The donut still fits in the groove between the dp and elbow, but the metal ring is now too small.

Is this metal ring necessary to properly mount the donut and provide a good seal?

 

[carlsbadGN]

Never mind, found the answer.