Now, since I really need a book titled automatic transmissions for dummies, does that mean I cannot buy individual parts to make a performance kit for my '64 904? Also, I would have the work done by a shop, since I feel this type of work is beyond, my level of expertise. I need to know what to tell someone to do to it.
You could definitely buy individual parts but there are probably kits that feature many upgrades. Of course a 400 hp transmission is a lot easier to source parts than a 500+ hp 904.