Thanks zetableh
Since you brought the thread back to life I might as well give the interim progress report on the G64/51 (from a 993TT) 6 speed installation:

For installing the bigger 6 speed gearbox some fabrication work was required. The torque bar (containing the torsion bars) in the 930 is in the way of installing the larger 6 speed and had to be cut a little. That means the Torsion bars needed to come out and therefore new coil over suspension is a pre-requisite for this transmission swap. I had full RSR suspension fitted in my car. That happened pretty quick, just a couple of days and that was done.
The fabrication for the mount for the new gearbox took a little longer but that's also done now and all painted nice and black like the rest of the car.

I also had SpeedWerks change the diff in the gearbox to a torque biased Guard unit. The last thing we are doing before putting the georbox in is change some gaskets in the box to ensure that the box is as good as new with no oil leaks etc. Here's a couple of pictures of the suspension and the gearbox. BTW, I just delivered a nice shiny RUF 6 speed shift knob to SpeedWerks yesterday. Once it's all back together again I may post another pic of the final product, although I don't know if that's really going to work out too well because when the parts are in, they obviously aren't so visible anymore.



Here you can see the code of the transmission: G64/51 - the one used in 993TT cars:



The rear RSR coilovers:



Here you can see the spring is rated at 550:



And one of the front ones:



You may have noticed the two ring like parts at the bottom end of the coils. The lowering of ride height happens simply by just turning those rings. Could not get much simpler I think even I could turn those things