I know 70AARCuda has 904 in his drag cars so I would look to him for heavy modifications. A lot of times you can get core transmissions for about $100. Personally I would look into like what I had like a 1976 904. I also had a 72 904 that I was going to rebuild but when I cracked open the 76 I could tell it had an extra clutch plate up front and it's accumulators were a little bigger. Again just trying to throw out the little experience that I have.
