Engine case distinctions
 

What if any is the difference between a 964 engine case 964-101-111-0R and a 964-101-111-1R? I have searched and found no good clearinghouse for different case numbers. I hope to build a new engine. With a rebuild does it make any difference which case I start with? I have a 1991 911 C2 964 Triptronic. All I know is that the engine case should be stamped with an M64/03 for one type of transmission and stamped M64/02 for I think the Triptronic. Any resources or information would be very helpful. Thanks Toma!!

I've never heard of any cc improvements, the castings wear out and a new casting # is used is about all