Any 833 4 speeds to avoid?

There is ONE other little tid-bit to keep in mind and that is the 1966 A-body 4-speeds. While they are a slip yoke design, they use a 904 style slip yoke...unlike the '67 and up, which use a 727 style slip yoke. Per Brewer's website (http://www.brewersperformance.com/history.htm)... The flange-style output was dropped for the 1966 models, and the slip-yoke tailshaft was introduced. The long tailshaft versions utilized the larger 30-spline output shaft (same as the 727 Torqueflite) and the short tailshaft version the 26-spline output shaft (same as the 904 Torqueflite). Having a '66 4-speed car, I can attest that the above comment is true. Every now and then, someone gets caught off guard on this one...but, they hold up just find behind a small block.