1977 904 horsepower limits?

Like any transmission, put enough money into it, and a 904 will take a ton of hp and torque. My ex-bosses car ran a 1200HP + Steve Schmidt pro-stock engine in his BA/A Pontiac and it had a 904 in it. It was a test mule for the performance automatic parts they make. He set a BA/A record with that car running the 904.
A lot of the SS/AA Cudas and Darts either had a highly modified 904 in it, or a 727 with 904 innards.