After some research there seems to be no definitive answer to this, however, both units appear identical and operate at the same temperature (88 deg) and I couldn't see any reason whatsoever why they wouldn't be interchangeable. So, with this in mind I kept an eye on ebay and decided to go for the first one that came up at a bargain price for my 2.0 JTS. Was lucky enough to find a brand new stat for less than a tenner so I thought it was worth a shot even though it was for the TS (60653946).
Various searches continually show this part no. doesn't apparently fit the JTS!
Examination of this TS part shows that it is more or less identical to the original JTS part I had fitted (60676066).
The question is "How much different can it be?"
So long as all the hoses and sensor connect then at the end of the day then surely it's just a stat that has to open at 88 degs.
So what is the difference?
The internals of my 60676066 (alfa original) seemed slightly different but it's a different manufacturer so I think that's understandable. Also, the radiator hose alignment notch is rotated by 90 degs but I believe this is also true of the original alfa TS version as this excellent thread shows in the photos (http://www.alfaowner.com/Forum/engin...twinspark.html). Easily sorted, just take a nick out the hose where required.
I have now fitted the new TS stat to my JTS and having taken the car on a short holiday have done close on 1K miles with no ill effects whatsoever and, as can be seen from the pics, it now runs at the right temp!
That's it, to my mind the Part No. 60653946 is directly interchangeable with Part No. 60676066 - but make your own mind up!
PS. Testing the faulty stat in the house showed that it was actually functioning (and not stuck) as it opened at around 72 degs. I had always assumed that when they failed the tended to fail open, but that didn't seem to be the case for me. It just got 'tired'.