Sounds like your getting alittle snippey with people who want to honestly help you. 904's are good transmissions,and I had a lock up one in a ramcharger that 175,000 when I got rid it
They all go bad sometime regardless of what it is.
The converter question was a honest question. My brother and I didnt set one in right in a Mustang he had. We were beginners and f--uped.
The car would back up all day long, wouldnt go forward..lol
It sound like it was ran without enough throttle pressure , but thats just a wild *** guess.
Hope you get it figured out!!!!