The G-50 gearbox has been used in one way another in 911s since 1987 until the end of the 997 gen cars. So there are lots of internal parts that can be used from one box to another, like gear sets, differentials, bearings, etc. Starting with the 991 Porsche used the PDK box and made it into a manual for cost savings.

If I had a GT3 I would definitely put the 3.89 R&P in it, yes. Well worth it! If you go from a 3.89 to a 3.44 and have the same gear ratios you will definitely notice it.

 

Some people r just clueless

 

Given your your car's hp limit, if you were not gear bound, how fast do you think this car could go?

I did a ED in 2001 on a 996 Turbo and I could run up to about 302kmh and that's about all she had...the acceleration at that point is so minimum that any minor incline or such would slow down the car.

 

To my recollection the manual states 314 kph/194mph. Seems reasonable, as it isn't until the the 180ies that the acceleration really slows down. It is fairly easy to hit the 186/300kph mark, so with the right gearing the car definitely will pass that and then some