I noticed on my classic the exhaust donut between the downpipe and centre section is fairly knackered, but it appears not to leak. After reading around it seems this only works because it is using standard nut and bolts to hold the center onto the end of the downpipe rather than the spring bolts that should be used and that allow the exhaust pieces to move somewhat.

Would I notice any reduced noise/vibrations or other improvements by replacing the gasket and using the correct spring bolts, rather than having the centre section bolted directly on, or shall I leave as it is?

If replacing the gasket does anyone know of a part number for a reasonably priced (read: NOT Subaru) gasket for the 2.5" donut? They must be fairly common on other cars.

 

by not having the bolts and spring setup just means the exhaust hangers are taking any rear thrust movement and you might even get a clunk of the exhaust where it hits the under the rear wishbones under hard acceleration

just look up 2.5" donut gasket on ebay, i got mine of there for £10. honda type R's use them

 

got an ebay gasket today. They are very good quality gaskets. Just don't buy the cheapest one on there.