Wow, I haven't been to this thread in a few months, looks like George Brown removed all of his posts, makes it appear as if I'm responding to a ghost.
In the 70's and 80's, I drove EPA test cars for Porsche. The man I worked was a Porsche of Germany compliance expert. In the "old" days, he went from race track to race track setting up all forms of Porsche race cars, including 550's.
When I was showing him my Spyder, he commented that the 5 speed wasn't available for that car, wasn't enough room for the 5th gear in the old trans housing. Of course, he's 80 years old and may have forgot???????