Toyota Repair: Maintenance on 1988 4Runner, front wheel bearing, toyota 4runner

Question
Ted,

How necessary is a valve adjustment on the 3.0 V6 for a 1988 Toyota 4Runner in terms of maintenance?  I know the repair manual recommends this every 60,000, but it seems pretty costly.

How critical is repacking the wheel bearings on the front?  This is also recommended at a specific interval.  Is this pretty straightforward for a dealer to do?

Also, I had the timing belt changed only 20,000 miles ago.  But I am only putting 5-6,000 miles per year on my runner.  At this rate it will be 10 years before I'm due for a new timing belt due to mileage.  However the repair manual recommends replacement after 6 years (I think).  Will the belt be shot after 6 years and only 30,000 miles?

Thanks for all your advice Ted, its a great help.

Answer
This engine uses different thickness shims on top of each valve, to change the valve clearance the shims are changed as necessary, this is time consuming and involves removing part of the intake chamber, they rarely go out of adjustment but on occasion they do due to wear on the vlaves in the valve seats etc.
Unless the engine has valve noise or is not running right I would wait until 120,000 miles and then have them checked and adjusted.
If this is a 4x4 the front wheel bearing service is much more time consuming than a 2WD model, the front hubs have to be disassembled and just about doubles the labor time of a 2WD model.
Time can also be a factor when considering certain parts such as belts and hoses, they can deteriorate with time due to environmental conditions, my recommendation would be to replace the timing/drive belts every 5 years.