Does anyone know if the 3 speed automatic gearbox in the 400/412 series is a generic one? And is there a 4 speed replacement that fits? I ask because the 3 speeder in the Porsche 928 had Mercedes internals, and there was also a 4 speed version fitted at a later date.
Search the body of posts in the archives, especially the old fchat. It's a GM automatic only slightly modified for Ferrari.
From my brief search of the archives, it appears it might be better to just wait for a 5 speeder to come along?