no offense Mike but leave the Cruiser questions to the Cruiser experts...lol
There are 4 different major birfield renditions...
69-75 US-Spec Drum front axles, coarse 10-spline birfields. FJ40-45-55's all ran these...also carried over into some overseas models - I know a guy in France with coarse spline drum fronts on a 81 FJ.
76-78 Disc front axles, fine spline birfields. (these have a slightly smaller bell diameter and slightly longer outer shaft than later models - FJ40's and FJ55's)
79 - 91 birfields, fine spline. All FJ40-55-60-62 AND minitruck birfields from this era are the same. Inner shaft lengths do vary however.
91+ 80-series birfs come in two varieties too....91-93 (I think) are the regular ones, 94+ units are setup for ABS functionality...not honestly sure what the difference is offhand....
NOTE in the above pic that the 77 FJ40 birf is noticeable longer in the shaft than the coarse spline 72 or in the Newfields.
In this pic, a 72 is on the left, then a 77, then a minitruck and finally a 2nd gen Newfield. The greased short-side image is a Longfield.