Hello transmission experts. I have a 1966 Fury 3 (318 Poly) wagon with a blowed up 727 trans. I can rebuild the current '66 727 but it has very limited options available for this year/model, particularly the torque converter. I plan an engine swap later this year so want to upgrade the trans now and use it for the summer. I have picked up a 78 727 from a motor home with low miles BUT it has the E-Brake on the tail-shaft. The question, is will my current '66 727 output shaft work with the modern heavy duty 727? I recall reading somewhere that the inner end of the shaft won't match up to gear cluster inside the trans. Does anyone know for sure?? I can pickup a more modern tailshaft and use that but need definitive info on this issue. Thanks for any help. I really appreciate it.