I've replaced the speakers in my 1989 without issue. The fronts are 4" speakers, and the rears I want to say are 6.5". If there are no screws holding the grill on, then it most likely has plastic locking pieces, just gently pull and it should pop off. In the kick panels (sides of the truck in front of the doors) there are 4 screws that held my stock speaker grill on.

- Jim


1989 Isuzu Trooper II
- 2.6L 4ze1 Motor
- BFGoodrich 235/75/15 AT