what's all interchangable among the c4 c5 and c6? I was wondering if the C6 planetarys are the same as the ones in the C4? can they be interchanged?

 

A C6 is very different from a C4/C5 transmission. All the parts are much larger, and the C8 uses a different system of bands and clutches, so nothing interchanges.

The C5 is basically a C4 with a lockup converter system, so many internal components are the same, but the hydraulic system isn't. Also, several of the internal parts vary even among C4's depending on the year model, so not all C4 components will swap around.

 

This site contains a great deal of info on the ford transmissions.
http://raceabilene.com/kelly/hotrod/trans.html