Originally Posted by holden997

that's correct,

I did some digging into the 997 work shop manual and extracted the following information on which engine has the old or revised larger IMS bearing:

Base engine (3.6) has designation "M96", has both the older IMS and revised larger bearing, you will need your engine number to determine which one you have:

Engine (3.6) number up to M96/05 69507475 has the older IMS bearing and Engine number from M96/05 69507476 has the larger revised IMS.

"S" engine (3.8) has designation "M97", also has both the older IMS and revised larger IMS bearing:

Engine (3.8) number up to M97/01 68509790 has the older IMS bearing and Engine number from M97/01 68509791 has the larger revised IMS.

The older IMS bearing can be replaced, this requires removing the transmission in order to get access to the bearing.

The larger IMS bearing can also be replaced but a tear down of the engine is required.

The work shop manual does not mention the date for the IMS changeover.

Originally Posted by mgordon18

I found this post over on 6speedonline. Skip down to post #8.

If someone can post up an example of an M96 engine on a 2005+ Carrera S or 4S, I'd love to see it. Similarly, I'd love to see an M97 engine on a non-S car.