I have a 1972 FJ40 and want to convert over to disc brakes. I have purchased a front axle off a 1985 FJ60. What do I need to do? All help is appreciated. :D

Short version:
-strip 72 axle to housing and diff. Keep inner axle shafts
-grind 72 axle housing balls to fit FJ60 birfields
-put all FJ60 parts back on
-figure draglink and tierod end
-bleed

longer version:

http://www.ih8mud.com/tech/minidisc1.php

or just outboard your springs a little and use the fj60 front.

Are the gears not different?

OEM for that year FJ60 is 3.73