I'm not in as big a hurry as SWUtah. I would at least wait till I got the coupon deal of the month from my Toyota dealer.
Factors to consider. Climate and whether or not the truck has been garaged. The SW heat and dryness are hard on rubber. Years do matter for rubber parts. How does your accessory belt look ? Has it ever had new tires ?
From Toyota Maintanence Guide Online
1998 Land Cruiser 90,000 Miles - 72 Months - Extensive Idling or Low-Speed Driving for Long Distances -> Replace timing belt
1999 Land Cruiser 90,000 Miles - 72 Months - Replace timing belt
2000 Land Cruiser 90,000 Miles - 72 Months - Replace timing belt
2001 Land Cruiser 90,000 Miles - 72 Months - Replace timing belt
2002 Land Cruiser 90,000 Miles - 72 Months - Replace timing belt
2003 Land Cruiser 90,000 Miles - 72 Months - Replace timing belt
2004 Land Cruiser 90,000 Miles - 108 Months - Replace timing belt
2005 Land Cruiser 90,000 Miles - 108 Months - Replace timing belt
2006 Land Cruiser 90,000 Miles - 108 Months - Replace timing belt
For 2004+ the belts can go 9 years! - Have the belts changed with different part numbers? or did they find that the belts are lasting longer than planned so they adjusted the maintanence interval.