How to distinguish transmissions in vintage 911's
 

Greetings forumers! This is my first posting as I am just entering the Porsche world. At my disposal I have a '71 911T that needs a bit of sprucing up prior to heading out for a fall cruise. On the list of things that need to be done are: new tires (recommendations?), new transmission linkage, and a new shift cable.

Now, you may think that the title of this posting would be straight forward, but the issue here is that this particular '72 has been retrofitted with a '74 2.7L engine. So, my question to you is this: How can one tell which transmission is in the car?

Thanks in advance!
-nick