Does any body know what year Toyota changed from the 10 spline pinion flange to the fine spline? And what the spline count is for the later one?

http://www.pirate4x4.com/forum/search.php?s=&action=showresults&searchid=71794&sortby=lastpost&sortorder=descending

I think they started fine spline pinion flanges in early 1978. My 12/78 has fine spline 4.10s.