I bought another 940 last week and, among many things, am replacing all of the exhaust except the cat. converter. The "sealing ring" between the cat. converter and header pipe is normally squeezed between two flanges and 3 bolts that can get very thin in the rust belt. My new purchase had something that is very impressive to do the job and the rusted flanges are not used. It is an R.G Gray "Flex Rolled V Clamp". The part no. on the clamp is 835811C2 and there is also a "48" and "YC2" on the clamp. The clamp appears to be stainless since there was no corrosion. Here is the URL:
http://www.breezehoseclamps.com/rg-ray/flex-seal-hose-clamps/
--
Mine: 3-940s running, 2-740 and 1-940 parts cars, and 3 1959 John Deere 630s (1 parts), dtr1:3-940s, dtr2:1-740, 1