Does anyone know if all the toyota radios are interchangable?

My 6 disc changer crapped out in my 99 4runner. I have the in dash system that has a separate radio/tape from the 6 disc changer (also in dash, below the radio/tape). I'm looking at a unit on ebay that is the same size as the two units in my dash but has the radio/tape/cd changer all in one unit (for a 2002 highlander). Are these systems interchangable?; my parts guy here in Boulder has no way to tell.

I looked at the connectors and they look the same, but the combo unit has a separate JBL amp (included in the auction). Ideas?

 

I would think it should work. They usually use the same unit, and you said the connections on the back are the same, except for the amp.

 

I have the combo CDplayer-tape-radio in my 86 4runner. Fit perfect!

 

did you just plug and play or did you have to repin the connectors? I am trying the same thing with an 98 Camry unit in my 89 runner any advice would be great. Thanks Bryan