I listed this before for $300. I need to move it out of my way for other projects. I have a Chevrolet 700R4 transmission from a 1991 Buick Roadmaster. The car belonged to a long time best friends Father-in-Law, his daughter wrecked the car. My friend told me that his Father-in-Law had the transmission rebuilt a little over a year before I bought it. Estimated mileage since it was rebuilt is well less than 20K. I bought the car to get the engine. He couldn't have been too hard on the transmission because he is 94 years old with one arm. I drove the car for about 30 miles and the transmission shifted excellent, no noises, slips or leaks.
I was going to use the transmission in a 57 Chevy but for the time being need to find a home for it. You will not be buying a pig-in-a-poke. I will guarantee the transmission to be good at the time of installation and will stand behind it. This does not mean a lifetime warranty. Transmission is located in Jeffersonville, Indiana across the river from Louisville, KY.