When I swapped from my 3 speed to my C4, I pulled all the clutch assembly out of my Bronco. Had to disassemble the pedal assembly to get the clutch pedal out. That was probably the most difficult part. But, still fairly easy. Then, the Auto is a plug and play. Only thing to concern yourself with is the shifter. I ran the B&M Mega Shifter on the floor. Came out SWEEEET!!! Has a ratchet shift for quick shifting without over shifting if you like to race.

I have a C4-D20 adapter in my storage. Honestly, it's BEST to find a C4-D20 already assembled (if that's the route you are going). But, if you find your self hunting for parts... let me know...