Are 833 and 904 yokes the same?

The early 66-67 26 spline is plenty strong for normal street use. I wouldn’t be afraid to throw 400-450 hp at one. Now if your talking about drag radial or slicks launches at high rpm, you might run into issues with output shaft damage. That being said, all A833 transmissions are pretty bulletproof . I’ve rebuilt many of each 26/30 spline transmissions and have never had either come in with broken output shaft.