71 up 2.47 to1 and 2.66 to 1

18 spline also known for hemi box where belong to 440 and hemis. And rest of 23s pretty much everything except the od main shaft drive usually smaller 26 spline same as 904s where the yokes slide in and early 64, 66 also has small spline 26s 67 and up has 30 spline same as 727s.
Pretty much as AJ has stated.