Ebay test pipe CNT racing catback wont mate properly

Hey guys im hoping you bunch of dapper gents can assist me in my quest to solve probably THE most annoying exhaust leak of all fucking time. Ive been trying to find an exhaust donut gasket to go between my eBay test pipe and my CNT racing exhaust i found a walker gasket that is a true 3” gasket however the outlet on the test pipe is spherical and the opening ID is 2.75” and the exhaust opening that mates to it is the same size i believe so the “true 3” dosnt fit and the test pipe wedges into the gasket and expands it till it breaks before the hardware is even close to tight has anyone found a gasket that will work between ebay test pipes and other exhausts? It has to be a donut gasket and realized but i cant for the life of me figure this out. Please help me it’s annoying the shit out of me haha

 

Pics help

 

This is what it looks like mated up but the donut gasket keeps blowing out around the exges because the spherical pipe pushes into it and expands it till it breaks. I figured out i need a gasket with an ID of 2.75” similair to the factory down lipe to test pipe gasket with the collar on one side that slips into the pipe and the donut on the other side i just dont know how to find said gasket based on the soecs i need. Ill have to call walker or felpro to see if they can give me a part number unless someone else happens to know another way

In that pic the angle is off because some ass hat cut the resonator out of the exhaust and replaced it with a 2.5 inch pipe. It has since been rectified and is now straight and 3” but it still gives the same result.

 

I didn't even use a donut gasket when i hooked my ebay pipe to my UR catback.

 

That downpipe weld looks like it was done by a knuckle dragger.

 

Yeah i know and they went from 3” to 2.5” too whoever did that probably calls his mom sister too. XD

 

I tried hooking it up like this and it was not leaking but when decelerating/down shifting whenever the rpms hit 1.8k-2k i got this super loud metallic vibration sound from it and it was driving me absolutely nucking futs.

 

That's strange. I know between like 2700-3000 rpm i get some absolutely disgusting NVH and similar noises but I don't think its the lack of a gasket.

 

You should get under and check it out i bet its probably contributing to it. I figured out how to seal it for now until i find a proper gasket i used a walker donut gasket part number 31364 and some permatex ultra copper as a gasket dressing just to be sure it will seal

 

I found after measuring and looking through Walker Catalog something close. Different application but same needs...a gasket.
Then Rock Auto under "Part Auto Search" Tab with Walker in search tree...if they had the one I wanted...

 

Thanks bro, yeah this is where i found the one im using now but it still dosnt fit quite as well as o would like it too. Im looking for one of the ones with the collar on one side and the dontut on the back and it looks like the biggest ID one the make is 2.5” i need a 2.75 inch as i dont want to put any restrictions in the system

 

I’m not too concerned about it tbh, I think it’s completely unrelated as well.