So look at it this way. Take a 1974 pig and a 1974 FJ40. The steering arms are interchangeable (I believe, but I'm not a pig guru). So Toyota didn't see a need to have differing Ackerman angles from the factory. Toyota also used the same brakes for 40s and 55s throughout their respective production runs.
At the end of the day with 33" tires on your 40 I doubt there is really much risk of breaking anything and really benefitting from the "larger" 60 series brakes, steering arms and Aisin lockouts vs. your Warns. In that case the easiest thing to do is leave things the way they are, maybe swap the ARB if you feel the 40 is going to see trails that would need a front locker.
On the other hand, I've been thinking about a good way of servicing the 60 series power steering components down the road on my own rig, and am pretty well convinced that the easiest/best thing for future maintenance will be to swap in 60 series knuckles and arms and get a new steering relay rod and all new 60 series TREs. That way I can buy a full set of 60 series TREs/rebuild kit and be done with it. Currently I would have to buy a 60/70 series TRE rebuild kit (and only use half of it) and three 40 series TREs (if I remember right and my memory is already getting fuzzy on this topic) if and when I ever have to replace the TREs on my rig. So in that instance maybe you really want 60 series components on BOTH rigs.
Rising Sun Bio
2F "Brahma" + Lockright, tach, Warn 8274, FJ60 Power Steering,
no more Sanden OBA
1FZ-FE factory lockers +
Safari intercooled turbo, CDL switch, cup holder, Metric TLC leather, heated seats, JDM switches, PUMA OBA.
Warn M12000 waiting for a bumper.
Limited TRD 2UZ-FE SOLD