Is there an auto trans out there that will "bolt on" without modification that has a 4th gear that can easily replace my C4 and fit on my driveshaft? I guess I am looking for the computer equivalent of a "plug and play". FYI I have a 3.55 rear gear. If so what year and car did it go on so I can start a part look up. Thanks
No plug and plays, do a rear tire swap, a 235x70x15 is 28" tall, or a 255x60x15 is 27" fits depending on your backspace, but kills some rpm on the highway and fills the fendewell .
And there are no OD transmissions out there that are as easy or as inexpensive to build as the C4. The AOD is the closest competitor and it will cost two to three times the cost of a comperable C4. May I ask why you are contimplating the change?