Transmission Recommended to Run Behind Built 360ci Engine in a 63 Valiant

Rob, is your 904 a v8 trans? The v8 and /6 are not interchangeable FYI. That being said given the choice I'll run a 904 rather than a 727 anyday. I'm running a 727 in my build only cause I got a hold of a rebuilt one for way less than rebuilding the 904 I had at the time.
727's soak up a lot of power in my experience but in factory form might have the advantage in durability. But you can build he 904 to handle more HP .