A later or longer H-M output shaft could be used but would necessitate shortening the driveshaft and adapting a larger universal slip joint yoke to fit the larger tailshaft.

From the October 1978 issue of HOT ROD: Part 2 of HOT ROD's guide for Powerglide automatic transmissions details step-by-step assembly procedures.

The planetary gearsets consist of two planetary gearsets. The output planetary carrier is linked to the output shaft. The reaction planetary carrier is linked to the low-reverse clutch pack.