The C4 will fit. You will have to modify the trany mount due that the trany mounts in a different place. You will see when you put them side by side.
You will also have to change the front yoke on the drive shaft. A special universal joint is needed. Same Universal as when you upgrade a Ranger To a 8.8 rear.
I took both ends with me.
The C4 shifter tab must be pointed down. Otherwise the shift pattern will be back wards. The tab on the C4 can be changed.
Remember that the C4 has lower gear ratio's so you might have to up your rear gear to get the same performance.
Why don't you go to a 4R70W? stronger than AOD + lower gear ratios.