So are you telling me to look for a 1971 up to 1979 727 SB trans from a car. Regardless of what year I find, I would have it gone through and it would receive a new 2400/2600 stall converter anyway.
It may have started in '78, but I believe it was most, but not all applications. One good thing about the later Torqueflites is that many 904s got a 2.74 low gear set! Not sure of which, most or if in all application. But a properly built 904 will work well behind a 340 and the car would be about .15 faster in the 1/4, if that's of any interest. But you'd also need a longer driveshaft and different trans yoke.
