Ford F150 - Timing belt change interval 2.3L

What do you guys recommend for a timing belt change interval?

Also, is a 1998 2.3L engine an interference engine? In other words, if the timing belt snaps will the pistons hit the valves? My son-in-law's Ranger has 89,000 miles, and is still on the original timing belt. I told him to get it changed ASAP.

I have had to replace my Chain 2x already in my '02 4.0L, something about the guides wearing prematurely, if there is absolutly no ticking or slapping noise coming from the front or rear of the block you should be fine, however, if you feel its necessary to replace it, then do as you wish.