Based on your parameters, there isn't an option. The non -electronic overdrive transmission list is a short one. 700-R4 or 200-4R. Both use the smaller TH-350 output shaft. You will need to change the drive shaft front yoke. Both use a TV cable to control shift points. It is critical that the geometry at the carb and cable adjustment are correct. The other option is an gear vendors overdrive for your TH-400. it also requires driveshaft modifications.