FWIW:
Jaguar E Type 5 Speed Gearbox | eBay

 

Is it really worth well over 4-5K, just to drop a few hundred rpm....? To me, 2,000 RPM at 60MPH, doesn't bother me a bit...I kind of like hearing the engine at speed....
If it was my daily driver , and I drove every day on a main highway, I might feel differently.
Edward

 

Agree! Too many other uses for $4-5K, when owning an E, or, any jag for the matter.