Are 1997 4 runners interchangeable with a 1999 4 runner?

1995 -2002 make up the third generation. For the most part yes, The 99 year had a optional multitrax trans AWD system you could get, and some bumper advancements, 1999 models received both major cosmetic and interior enhancements. A new "fat lip" bumper was designed to allow for an extended crush zone on the front of the frame, as well as new multi-parabola style headlights, projector style fog lamps, and updated side marker lights and front turn signals. Vehicles with "Limited" and "Highlander" (later called "Sport Edition") trim received color-keyed running boards, front and rear bumpers, mud flaps and flares. The ergonomics of the interior was completely changed, moving all the controls to the center of the dash for the rear window, and defrost. The Limited trucks also received a brand-new electronic temp control, and upgraded stereo. 1997 models received a few minor updates, including the addition of a color keyed cargo cover. 1998 remained largely unchanged, save for a few changes in the electronics. More ergonomic switch control panels and a newly designed 4 spoke steering wheel, which also necessitated a redesign of the air bag system.