Tasty 3rd gen!

[AndyLala]

4" in the back same as the fronts. You'll have to take the side trims out, or at least move them into the middle. If you've gone to all that trouble, a little bit of work on the speaker boxes (shave the speaker mount turret off flush with the rest of the box - unwire the built in amp) and you can get 5 1/4" speaker in there, provided they don't stick out too much...

[Snoop]

4" in the back same as the fronts. You'll have to take the side trims out, or at least move them into the middle. If you've gone to all that trouble, a little bit of work on the speaker boxes (shave the speaker mount turret off flush with the rest of the box - unwire the built in amp) and you can get 5 1/4" speaker in there, provided they don't stick out too much...

Yeah, I did this. I took the standard boxes out completely and fabricated some MDF panels to fit component mids instead (tweeters are mounted in the section above the tailgate window). They sound great but just sometimes when cranked up I can hear them catching the side panels. I will move the speakers to be mounted slightly further back. I also dynomatted behind where the speakers were mounted. Can never have too much dynomat!

[da SLUG man]

I've seen a lot of pics of that one before - it is only 2WD...

did wonder where the transfer lever was!... though maybe the petrol 4runner had a different setup... cos that's a different gear selector too.