Wecome to the group. It may be worth looking into a 914 tranny to get the 5th gear. I had a friend who put one into a Karmin Ghia. He did it so he could get up to 150MPH in 5th when racing, but it would be good at normal highway speeds. He used the nose cone off a 912 as the 914 tranny is normally in the rear of the car.
__________________
|