I found the 5 speed and was told its only got one bolt difference.
But I cant find the 6 speed or what bolt..

Anyone help ?

5 speed on the left, 6 speed on the right. This is a 2001-2008 Boxster S/Cayman S 6 speed. Other years have a different shape and bolt pattern.

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How else can you tell the differences between the 2 transmissions ?

You are making this more difficult than it really needs to be....

They are going to have different part numbers which I am sure you could google.

I would think anyone selling a Boxster transmission is going to know if it is a 5 or 6 speed.

One could always row the gears and count.

Did you find someone with a pile of 100 transmissions and they cannot figure which is 5 or 6 speed?

6 speed on the left.

6 speed is a 466 P/N
5 speed is an 012 P/N