| St4 and ST4S cans have a larger diameter pipe where they join the collector box. There is a very obvious flare of the pipe at the end. These cans appear to be the same diameter all the way to the end. Its difficult to see as its not a fantastic picture on ebay so i might be totally wrong!
You could make up an adapter if they are wrong though.
Here is a pic of my spare ST4 cans for comparison. |