The '68 Goat I bought a few months ago came with a High Horsepower Jim Butler 474 and a Highly Modified 200 4R transmission. After a summer of fun with this car the transmission is starting to slip pretty bad. I was able to pick up a real nice TH400 out of a '69 goat that I'm planning on having rebuilt. I've always heard the TH400 is the toughest tranny and what should be in this car. I realize I'll loose the overdrive but it's not a big concern, the car is only driven about 1500 miles a year. Besides the overdrive, are there any advantage to using the 200 4R? Anybody have any luck with these transmissions? Which transmission would you use?